blabbermouthed Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition adjective. talking too much or revealing secrets. Example Sentence She is always blabbermouthed in class. More Example Sentences She got in trouble for being blabbermouthed. Synonyms talkative; loquacious; garrulous Antonyms quiet; reserved; silent Hear It! Say It! Write It! blabbermouthed Switch to cursive Start Share with your friends: