Definition of volatile for English Language Learners. : 1  likely to change in a very sudden or extreme way. : 2  having or showing extreme or sudden changes of emotion. : 3  likely to become dangerous or out of control.
expletive (comparative more expletive, superlative most expletive) 1  Serving to fill up, merely for effect, otherwise redundant. 2  Marked by expletives (phrase-fillers).
exÂ·piÂ·raÂ·tion. (Äkâ²spÉ-rÄâ²shÉn) n. 1. The act of coming to a close; termination: the expiration of a contract. 2. The act of breathing out; exhalation.