[*] 106. Nouns that vary in Gender are said to be heterogeneous. 1 [*] a. The following have a masculine form in -us and a neuter in -um: balteus , cāseus , clipeus , collum , cingulum , pīleus, tergum , vāllum , with many others of rare occurrence. [*] b. The following have in the Plural a different gender from that of the Singular:—
balneum (N.), bath; | balneae (F.), baths (an establishment). |
caelum (N.), heaven; | caelōs (M. acc., Lucr.). |
carbasus (F.), a sail; | carbasa (N.) (-ōrum), sails. |
dēlicium (N.), pleasure; | dēliciae (F.), pet. |
epulum (N.), feast; | epulae (F.), feast. |
frēnum (N.), a bit; | frēnī (M.) or frēna (N.), a bridle. |
iocus (M.), a jest; | ioca (N.), iocī (M.), jests. |
locus (M.), place; | loca (N.), locī (M., usually topics, passages in books). |
rāstrum (N.), a rake; | rāstrī (M.), rāstra (N.), rakes. |