[584]. pecus, beast, is feminine; also tellūs, earth, and the substantives in -ūs which have -ūdis ([475]) or -ūtis ([477]) in the genitive: as, palūs, marsh; iuventūs, youth.
[STEMS IN -u-.]
The Fourth Declension.
Genitive singular -ūs, genitive plural -u-um.
[585]. Stems in -u- are substantive only, and mostly masculine.
[586]. There are only three neuters in common use, cornū, horn, genū, knee, and verū, a spit. But some cases of other neuters are used: as, ablative pecū, flock; plural nominative and accusative artua, limbs (Plaut.); OSSVA, bones (inscr.).
[587]. The nominative of stems in -u- ends, including the stem vowel, in -u-s in gender words, and in lengthened -ū of the stem in neuters.
[588]. Most substantives in -u- are masculines in -tu- or -su-, often defective in case ([235]). The following words are feminine: acus, pin, needle, domus, house, manus, hand, porticus, colonnade; tribus, tribe; and the plurals īdūs, ides, and quīnquātrūs, feast of Minerva; rarely penus, store, and specus, cave.
[589]. Stems in -u- are declined as follows:
| Examples Stems | flūctus, wave, flūctu-, M. | cornū, horn, cornu-, Ne. | Stem and case endings | |
|---|---|---|---|---|
| Singular | M. | Ne. | ||
| Nom. | flūctus, a (or the) wave | cornū | -us | -ū |
| Gen. | flūctūs, a wave’s, of a wave | cornūs | -ūs | -ūs |
| Dat. | flūctuī, -ū, to or for a wave | cornū | -uī, -ū | -ū |
| Acc. | flūctum, a wave | cornū | -um | -ū |
| Abl. | flūctū, from, with, or by a wave | cornū | -ū | -ū |
| Plural | ||||
| Nom. | flūctūs, (the) waves | cornua | -ūs | -ua |
| Gen. | flūctuum, waves’, of waves | cornuum | -uum | -uum |
| Dat. | flūctibus, to or for waves | cornibus | -ibus | -ibus |
| Acc. | flūctūs, waves | cornua | -ūs | -ua |
| Abl. | flūctibus, from, with, or by waves | cornibus | -ibus | -ibus |