HETEROGENEOUS Nouns, one of the three variations in irregular nouns; or such as are of one gender in the singular number, and of another in the plural.—Heterogeneous, under which are comprehended mixed nouns, are sixfold. 1. Those which are of the masculine gender in the singular number, and neuter in the plural; as, hic tartarus, haec tartara. 2. Those which are masculine in the singular number, but masculine and neuter in the plural; as, hic locus, hi loci et haec loca. 3. Such as are feminine in the singular number, but neuter in the plural; as, haec carbasus, et haec carbasia. 4. Such nouns as are neuter in the singular number, but masculine in the plural; as, hoc caelum, hi caeli. 5. Such as are neuter in the singular, but neuter and masculine in the plural; as, hoc rostrum, hi rostri, et haec rostra. And, 6. Such as are neuter in the singular, but feminine in the plural number; as, hoc epulum, haec epulae.