PETTY definition: of little or no importance or consequence. See examples of petty used in a sentence. The meaning of PETTY is having secondary rank or importance : minor, subordinate. How to use petty in a sentence. If you describe someone's behavior as petty, you mean that they care too much about small, unimportant things and perhaps that they are unnecessarily unkind. of little or no importance; inconsequential: petty grievances. of lesser importance or merit; minor: petty considerations. having or showing narrow ideas, interests, etc.: petty minds. ungenerous in … petty adjective (SELFISH) selfish and mean, esp. because of having too much interest in small and unimportant matters: Definition of petty adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more. 2 days ago · Adjective petty (comparative pettier or more petty, superlative pettiest or most petty) (often derogatory) Having little or no importance. [from 16th c.] Petty definition: Of small importance; trivial.