21.04.24: third declension adjectives [1]

Third declension adjectives are the last of the adjective declensions. They all take the same endings but there is a difference in the nominative singular. Here are three third declension adjectives:

[1] audāx: bold, daring; only one form for masculine, feminine and neuter

[2] fortis [masculine and feminine], forte [neuter]: brave, strong; two forms (i) for masculine and feminine (ii) for neuter

[3] celer [masculine], celeris [feminine], celere [neuter]: fast; three forms, a different ending for all three genders

Therefore, …

[1] audāx is an adjective of one termination

[2] fortis, forte is an adjective of two terminations

[3] celer, celeris, celere is an adjective of three terminations

Those are the expressions used in grammar.

(I used to note these as, for example: fortis, -e [3/2t] i.e. it’s a third declension adjective with two terminations. That’s not a standard way of doing it, but that’s what I used.)

Below are some examples of third declension adjectives.

One termination

Adjectives of one termination can, like 3rd declension nouns, have a variety of forms in the nominative singular.

audāx: bold; daring; reckless

caelebs: unmarried; single.

dīves: wealthy

fēlīx: happy

prūdēns: wise

vetus: old

Two terminations

Adjectives of two terminations, to which by far the largest group of 3rd declension adjectives belong, have a nominative singular in -is for masculine and feminine, and -e for neuter.

brevis, -e: short; brief

crūdēlis, -e: cruel

difficilis, -e: difficult

facilis, -e: easy

fidēlis, -e: faithful; loyal

fortis, -e: brave; strong

gravis, -e: grave; heavy

levis, -e: light (not heavy)

nōbilis, -e: noble

pinguis, -e: fat; plump

trīstis, -e: sad

Three terminations

There are very few 3rd declension adjectives of three terminations; all of them end in -er in the masculine, -is in the feminine and -ein the neuter; note that, with the exception of celer, the -er ending, like some 2nd declension masculine nouns, loses the -e- when an ending is added.

celer, celeris, celere: fast; swift

Note the loss of the /e/ in the others:

acer, acris, acre: sharp; bitter; keen; eager; cruel

alacer, alacris, alacre: lively; brisk; cheerful; eager

celeber, celebris, celebre: famous

paluster, palustris, palustre: swampy; marshy

volucer, volucris, volucre: winged; able to fly