3rd Declension: Gender

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84. The Gender of nouns of this declension must be learned by practice and from the Lexicon. Many are masculine or feminine by nature or in accordance with the general rules for gender (§ 31). The most important rules for the others, with their principal exceptions, are the following.1

85. Nouns in -or, -ōs, -er, -ĕs (gen. -itis), -ex (gen. -ĭcis) are masculine.

color, flōs, imber, gurges (gurgitis), vertex (verticis).


a. The following are feminine.

Arbor, cōs, dōs, linte 

b. The following are neuter:

Ador, aequor, cor, marmor, ōs (ōris)


os (ossis), cadāver, iter, tūber, ūber, vēr

and names of plants and trees in -er.

acer, papāver

86. Nouns in , -ās, -ēs, -is, -ūs, -x, and in -s preceded by a consonant are feminine.

legiō, cīvitās, nūbēs, avis, virtūs, arx, urbs

The nouns in are mostly those in -dō and -gō, and abstract and collective nouns in -iō.


a. The following are masculine:

leō, leōnis
ligō, -ōnis
sermō, -ōnisa


cardō, harpagō, margō, ōrdō, turbō

and concrete nouns in -iō.

pugiō, ūniō, papiliō2

In addition,

acīnacēs, ariēs, celēs, lebēs, pariēs, pēs

nouns in -nis and -guis:

īgnis, sanguis


axis, caulis, collis, cucumis, ēnsis, fascis, follis, fūstis, lapis, mēnsis, orbis, piscis, postis, pulvis, vōmis.

Mūs is masculine, as are:

calix, fornix, grex, phoenīx

and nouns in -ex (gen. -icis) (see § 85 above).


dēns, fōns, mōns, pōns.

 Note— Some nouns in -is and -ns which are masculine were originally adjectives or participles agreeing with a masculine noun.

Aprīlis [sc. mēnsis] (m.) April
oriēns [sc. sōl] (m.) the east
annālis [sc. liber] (m.) the year-book

b. The following are neuter.

vās (vāsis)
crūs, iūs, pūs, rūs, tūs

87. Nouns in -a, -e, -l, -n, -ar, -ur, -ŭs are neuter.

poēma, mare, animal, nōmen, calcar, rōbur, corpus

Also lac and caput.


a. The following are masculine.

sāl, sōl, pecten, vultur, lepus

b. The following is feminine.

pecus (gen. -udis)



1.Some nouns of doubtful or variable gender are omitted.

2. Many nouns in (gen. -ōnis) are masculine by signification.

gerō carrier
restiō ropemaker

And family names (originally nicknames).

Cicerō, Nāsō. See § 236.c, § 255

Suggested Citation

Meagan Ayer, Allen and Greenough’s New Latin Grammar for Schools and Colleges. Carlisle, Pennsylvania: Dickinson College Commentaries, 2014. ISBN: 978-1-947822-04-7. https://dcc.dickinson.edu/grammar/latin/3rd-declension-gender