[487]. (2.) Stems in -r- and -s- are declined as follows:
| Examples Stems | pater, father, patr-, M. | dolor, pain, dolōr-, M. | flōs, flower, flōr-, M. | genus, race, gener-, Ne. |
|---|---|---|---|---|
| Singular | ||||
| Nom. | pater | dolor | flōs | genus |
| Gen. | patris | dolōris | flōris | generis |
| Dat. | patrī | dolōrī | flōrī | generī |
| Acc. | patrem | dolōrem | flōrem | genus |
| Abl. | patre | dolōre | flōre | genere |
| Plural | ||||
| Nom. | patrēs | dolōrēs | flōrēs | genera |
| Gen. | patrum | dolōrum | flōrum | generum |
| Dat. | patribus | dolōribus | flōribus | generibus |
| Acc. | patrēs | dolōrēs | flōrēs | genera |
| Abl. | patribus | dolōribus | flōribus | generibus |
[488]. Many stems in -r- ended originally in -s-, which became -r- between two vowels, and in some words in the nominative also ([154]): as, flōs, M., flower, G. *flōsis, flōris; honōs, M., honour, G. honōris, N. honor.
[489]. (a.) Examples of stems in -r-, with nominative -r, genitive -ris, are:
| -ar, -aris | baccar, Ne., a plant; iūbar, Ne., rarely M., bright sky, no Pl. |
| -ār, -aris | lār, M., household god; G. Pl. larum; two or three times larium. |
| -ār, -arris | fār ([171], [1]), Ne., spelt; Pl. only N. and Ac. farra. |
| -er, -eris | Masculines: acipēnser, sturgeon; agger, mound; ānser, rarely F., goose; asser, pole; carcer, jail; later, brick; mulier, F., woman; passer, sparrow; vōmer, ploughshare. Neuters: cadāver, corpse; tūber, swelling; ūber, breast; verberis, G., lash, no N., generally Pl.; acer, maple, and some other plant names: see [573]. pauper, poor, adjective. |
| -ter, -tris | accipiter, M., hawk; frāter, M., brother; māter, F., mother; pater, M., father. |
| -ēr, -ēris | vēr, Ne.; no Pl. |
| -or, -oris | aequor, Ne., sea; marmor, Ne., marble; arbor, F., tree. |
| -or, -ōris | olor, M., swan; soror, F., sister; uxor, F., wife. Many masculines in -or for -ōs ([237]): as, odor, smell; and in -tor, -tōris ([205]): as, amātor, lover. Also gender comparatives of adjectives: as, trīstior ([346]), M., F., sadder. |
| -ur, -oris | Neuters: ebur, ivory; Pl. only ebora; rōbur, heart of oak; Pl. rōbora common, rōborum and rōboribus twice each. Also femur, thigh, femoris or feminis, and iecur, liver, iecoris, iecineris, or iocineris. |
| -ur, -uris | augur, M., F., augur; furfur, M., bran; turtur, M., F., turtle-dove; voltur or vultur, M., vulture. Neuters: fulgur, lightning; guttur, rarely M., throat; murmur, murmur; sulpur, sulphur. cicur, tame, adjective. |
| -ūr, -ūris | fūr, M., thief. |
[490]. volucris, F., bird, stem volucr-, has its nominative formed like that of -i- stems.
[491]. (b.) Examples of stems in -s-, or -r- for -s-, with nominative -s, genitive -ris, are:
| -aes, -aeris | aes, Ne., copper, bronze; in the Pl. only aera and aerum are usual. |
| -ēs, -eris | Cerēs. pūbēs, mangrown; impūbēs, immature, adjectives; for the last more commonly impūbis, like brevis ([630]). |
| -is, -eris | cinis, M., ashes; cucumis, M., cucumber, also with -i- stem; pulvis, M., dust; vōmis, M., ploughshare. |
| -ōs, -oris | arbōs, F., tree. |
| -ōs, -ōris | Masculines: flōs, flower; mōs, custom; rōs, dew, no G. Pl. ([430]); lepōs, grace; honōs or honor, honour, and some old Latin words for later -or: as, odōs or odor, smell ([489]). ōs, Ne., mouth, face, no G. Pl. ([430]). |
| -us, -eris | Neuters: acus, husk; foedus, treaty; fūnus, funeral; genus, race; glŏ̄mus ([134]), clew; holus, green stuff; latus, side; mūnus, gift; onus, burden; opus, work; pondus, weight; raudus or rūdus, piece of copper; scelus, crime; sīdus, constellation; ulcus, sore; vellus, fleece; vīscus, bowel, usually plural; volnus or vulnus, wound. Also Venus, F., and vetus, old, adjective. |
| -us, -oris | Neuters: corpus, body; decus, grace; dēdecus, disgrace; facinus, deed; faenus, interest; frīgus, cold; lītus, shore; nemus, grove; pectus, breast; pecus, flock; penus, store; pignus, pledge; stercus, dung; tempus, time; tergus, back. Also lepus, M., hare. |
| -us, -ōris | Neuter comparatives of adjectives: as, trīstius ([346]), sadder. |
| -ūs, -ūris | Neuters: crūs, leg; iūs, right, Pl. iūra, G. Pl. twice only (Plaut.; Cato), no D. or Ab. Pl.; iūs, broth, pūs, pus, rūs, country, tūs, frankincense, Pl. only N. and Ac. iūra, &c. tellūs, F., earth. |
[492]. vās, Ne., vessel, utensil, retains the s between two vowels: G. vāsis, D. vāsī, Ab. vāse, plural N. and Ac. vāsa; the G. vāsōrum, and D. and Ab. vāsis, are formed from an -o- stem, vāso- ([401]). mēnsis, M., month, mēnsis, has its nominative formed like that of -i- stems; G. Pl. mēnsum, sometimes mēnsuum or mēnsium. os ([171, 1]) Ne., bone, ossis, has no G. Pl. in good writers ([430]): ossium late.
[493]. The two neuters vīrus, gall, poison, and volgus or vulgus, the crowd, have -o- stems, except in the nominative and accusative ([401]), and no plural: thus, N. and Ac. volgus, G. volgī, D. and Ab. volgō. A masculine accusative volgum is sometimes found. The Greek neuter pelagus, the deep, has also G. pelagī, D. and Ab. pelagō, Pl. N. and Ac. pelagē ([508]).