datemark Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. a mark indicating the date of an event. Example Sentence The datemark on the milk carton showed it had expired. More Example Sentences Each datemark helps us track important events. Synonyms timestamp; date stamp; record Antonyms remove; erase Hear It! Say It! Write It! datemark Switch to cursive Start Share with your friends: