Latin-style plurals for masculine-feminine pairs.
Many Latin nouns ending in -us which describe a person are second-declension masculine, and have a plural in -i. They often have a first-declension feminine counterpart in -a, -ae. These nouns sometimes come from adjectives of the first-second declension.
Many Latin nouns ending in -tor which denote a person engaging in activity are third-declension masculine and have a plural in -tores. They sometimes have a third-declension feminine counterpart in -trix, -trices.
In partial analogue, many Latin nouns ending in -sor denote a person engaging in activity, are third-declension masculine, and have a plural in -sores. However, they rarely have a corresponding feminine form.
The following are from Latin third-declension comparative adjectives that have the same form in the masculine and feminine (although not necessarily the neuter). In English they are sometimes used as nouns, sometimes adjectives. Shown for each is the common masculine-feminine form. Opposites are listed on the same row.