IMPULSIVE definition: 1. showing behaviour in which you do things suddenly without any planning and without considering…. Learn more. The meaning of IMPULSIVE is arising from an impulse. How to use impulsive in a sentence. Synonym Discussion of Impulsive . impulsive definition: acts on sudden desires without thinking first. Check meanings, examples, usage tips, pronunciation, domains, and related words. Discover expressions like " impulsive speech". spontaneous, impulsive, instinctive, automatic, mechanical mean acting or activated without deliberation . spontaneous implies lack of prompting and connotes naturalness.