ETYM Latin suffixus, p. p. of suffigere to fasten on, to affix; sub under + figere to fix: cf. French suffixe. Related to Fix.
1. A letter, letters, syllable, or syllables added or appended to the end of a word or a root to modify the meaning; a postfix.
2. A subscript mark, number, or letter.
Letter or group of letters added to the end of a word in order to show its tense (“passed”), form the plural (“children”), change the part of speech (“wonderful” adjective; “wonderment” noun), or form a new word (“sexist”).