legions Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. 1 an army unit in ancient Rome that was made up of soldiers on foot and on horseback; 2.any large group of people or things. Example Sentence The emperor sent his legions into battle. Synonyms numerous; many; mob; army; brigade Antonyms few Hear It! Say It! Write It! legions Switch to cursive Start Share with your friends: