Third Declension Nouns
Nouns which can be either masculine
or feminine are called common nouns. Nearly all are in the third
declension. Often context alone will determine which gender is intended.
For example, sacerdotes in templo Bonae Deae sunt means “The
priestesses are in the temple of the Good Goddess”, but only because
her rites were forbidden to men. sacerdos is the most frequent
example of a common noun in ancient grammars, being used most significantly
in Donatus’ Ars Minor, a basic grammar of lasting influence.
Over a thousand years later, it was the second book printed by Gutenberg,
and the first ever printed in England. Donatus was St. Jerome’s teacher,
but it is not known whether he himself was a Christian.
Even so, when grammar teaching
became the preserve of Christian monks, the existence of priestesses
will have come to seem a strange idea, and homo, hominis
became the standard paradigm for such nouns, on the analogy of ἄνθρωπος
(anthropos “human being”), so used in Greek grammars. Whereas,
really is a common noun, being used freely to refer specifically to
both men and women, homo is rarely, if ever, feminine other than
in grammar books.
In memorising the genitive
singular of third declension nouns, it often helps to recall cognate
English words, since they tend to draw on the stem of the Latin noun,
not on its nominative form; to take some examples from the vocabulary
given in this chapter, note military, regal, nocturnal,
pacify, capital, corporal, itinerary, illuminate,
Be careful not to confuse the
third declension gen. pl. ending -um as it appears in words such
as dolorum, laborum, uxorum with the second declension
gen. pl. ending -orum (as in dominorum, saxorum).
In determining the gender of
third declension nouns, it helps that some common terminations are found
mostly or exclusively with nouns of a particular gender; for example,
nouns in -or, -oris
tend to be masculine (but note the exceptions soror, uxor,
also arbor [which has a short o in its stem]). As these
words show, even when there is a natural gender, words may share the
same forms; note also that pater, patris “father”
and frater, fratris “brother” are masculine, whereas
mater, matris “mother” is feminine;
nouns in -tas -tatis,
and -tio -tionis, and -tudo -tudinis and
-tus -tutis are feminine and mostly abstract;
a 3rd decl. nom. sing.
in -us is usually neuter (but be careful not to confuse e.g.
corpus or tempus with masculine nouns of the second or fourth
[see Chapter 11] declension).
The need to learn the gender
of nouns is perhaps, after the concept of inflection, the most challenging
aspect of learning Latin for speakers of English, which is so little
concerned with gender. Native speakers of languages which mark gender
tend to learn the gender of individual words gradually, through experience;
even so, the problem must have presented certain difficulties to the
Romans themselves, since more than one ancient grammarian observes that
schoolboys were encouraged to remember that almost all nouns have the
same gender in both their basic and their diminutive form; for example,
amphora, -ae fem. 1 “jar” and ampulla, -ae
fem. 1 “small jar”, filius, -i masc. 2 “son” and
filiolus, -i masc. 2 “dear little son”, liber,
libri masc. 2 “book” and libellus, -i, masc. 2
“booklet”, pars, partis fem. 3 “part” and particula,
-ae fem. 1 “particle”.
fem. 3 “finger- or toe-nail” and ungula, -ae fem.
1 “hoof” follow the same pattern; interestingly, however, the diminutive
form refers to the bigger object (compare castellum, -i
neut. 2 “castle” and castrum, -i neut. 2 “fort”,
obelus, -i masc. 2 “roasting-spit” and obeliscus,
-i masc. 2 “obelisk”).
A rare exception, noted by
the grammarians, is rana, -ae fem. 1 “frog”, which
has the masculine diminutive ranunculus, -i 2 “little
frog”. The feminine deminutive form ranula does, however, survive
in English as the term for a swelling on the tongue of cattle, so called
either because it is frog-shaped or because cows croak when afflicted
This trick for determining
gender shows how important diminutives must have been in colloquial
Latin. Nowadays, of course, we know so little about spoken Latin, so
it is hardly of use to modern students. The importance of diminutives
can also be seen in their use in the development of the Romance languages;
note, for example, such basic words as the French cerveau and
cervelle “brain[s]”, both derived from cerebellum, -i
neut. 2., rather than cerebrum, -i neut. 2, oiseau
“bird” from avicula, -ae fem. 1, rather than avis,
avis fem. 3, also grenouille
“frog” from ranunculus, rather than rana, but with
the original feminine gender restored. Modern French uses diminutives
markedly more sparingly than do other Romance languages, as indeed does
English, even though they are so common in German as not normally to
have their own lemmata in dictionaries.
English words such as “homogeneous”
and “homosexual” are not derived from the Latin noun homo,
hominis, but come from a quite unrelated source, the Greek adjective ὁμός
(homos), “same”. homo means “man” in the sense
“human being”, regardless of gender. The standard school-example
of a definition was homo est animal rationale, mortale, risus
capax “Man is an animal, rational, mortal and capable of laughing”;
a ninth century grammar written in France offers the alternative
porcus est animal mortale, irrationale, cibum capiens, quadrupedale,
grunnibile “A pig is an animal, mortal, irrational, food-taking,
four-footed and capable of grunting”. A far more famous pig-parody
is the Testamentum Porcelli “The Little Pig’s Will”, which
is still extant; deploring their lack of interest in serious literature,
St. Jerome complains in the preface to the 12th book of his commentary
on Isaiah (and elsewhere) that testamentum ... Grunnii Corocottae
porcelli decantant in scholis puerorum agmina cachinnantium
“hordes of giggling schoolboys chant The Will of the Little Pig
Grunnius Corocotta”.) Few modern readers find the TP even
While caput survives
in many modern words (in English, for example, in “chapter”, “chief”,
“decapitate”, “recapitulate”), the Italian word for “head”,
testa, and the French, tête, are derived, rather comically,
from the Latin testa, -ae fem. 1 “pot”; similarly,
the German word for “head”, Kopf, preserves the late Latin
cuppa, -ae fem. 1 “cup”. Haupt, which Kopf
supplanted, is derived from the same IndoEuropean root as “head”
Nouns such as ars,
arx, civis, classis, often called “third declension
i-stem” nouns, were originally a separate declension, but they
are distinct from most other third declension nouns only in having the
genitive plural ending -ium, not -um, and sometimes the
ablative singular ending -i, not -e. This latter variation
is best learned through observation. For now, it is best to assume that
all such nouns have -e as their ablative singular ending, but
that most with the same form in the nominative and genitive singular
(e.g. hostis, ignis) allow both -e and -i
in the ablative singular.
There was sometimes uncertainty
about the formation of the genitive plural in the third declension.
Julius Caesar stated that the gen. pl. of panis, panis
masc. 3 “bread” is panium, whereas Verrius Flaccus, who was
tutor to Augustus’ grandsons, ruled in favor of panum. There
were other grammarians who argued that neither is correct because
panis has no plural, being weighed (like aurum “gold”,
argentum “silver”; see Chapter 10), not counted. This last opinion
is strangely removed from reality: loaves of very modern looking, if
rather overbaked, bread have survived in Pompeii.
No account is taken here of
the variant endings -im for -em and -īs for -es
in the accusative singular and plural respectively of some third declension
masculine and feminine nouns. The Romans themselves were inconsistent.
The critic Valerius Probus says that we should trust our ear in such
matters and not the “rotten rules in the cesspits of grammar” (non
finitiones illas praerancidas neque fetutinas grammaticas), and
it is only because he consulted a copy of Vergil’s poetry with corrections
in the poet’s own hand that he can assert that Vergil wrote turrim
rather than turrem, and sometimes urbīs
rather than urbes (Aulus Gellius, Attic Nights 13.21).
For examples of variant forms and spellings, see the file elsewhere
hostis signifies a foreign
enemy of the state; a personal enemy is inimicus, inimici
masc. 2 (i.e. the negative prefix in + amicus).
The noun animal is derived
from the third declension adjective animalis, -e “animate”;
hence, the similarity of its declension to that of such adjectives (abl.
sing. in -i, gen. pl. in -ium; see Chapter 9) is all the