equester, cavalry-
palūster, of a swamp
pedester, foot-
puter, rotten
silvester, woody
terrester, land-
So also celer, swift. The names of months, September, Octōber, November, December, are also adjectives with stems in -bri-, but are not used in the neuter. Other adjectives with stems in -bri-, -cri-, or -tri-, have no distinctive form for the masculine nominative singular: as, muliebris, mediocris, inlūstris.
[628]. These adjectives are declined as follows:
| Example Stem | M. ācer, F. ācris, Ne. ācre,sharp ācri-. | |||||
|---|---|---|---|---|---|---|
| Singular. | Plural. | |||||
| Masc. | Fem. | Neut. | Masc. | Fem. | Neut. | |
| Nom. | ācer | ācris | ācre | ācres | ācres | ācria |
| Gen. | ācris | ācris | ācris | ācrium | ācrium | ācrium |
| Dat. | ācrī | ācrī | ācrī | ācribus | ācribus | ācribus |
| Acc. | ācrem | ācrem | ācrem | ācrīs, -ēs | acrīs, -ēs | ācria |
| Abl. | ācrī | ācrī | ācrī | ācribus | ācribus | ācribus |
[629]. In all cases but the masculine nominative singular these adjectives are just like those in -i- ‘of two endings’ ([630]). But the ablative always has -ī, never -e, and the genitive plural always has -ium, never -um. In celer the second e belongs to the stem: M. celer, F. celeris, Ne. celere; the genitive plural, which is celerum, is found only as a substantive. Most of these adjectives have now and then a masculine in -is, like adjectives ‘of two endings’ ([630]), and in old Latin the nominative -er is rarely feminine.