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).
The true profane expletive words are usually used to curse, shock, offend, and often to hurt another person. Because of this, they are considered bad. In some countries, all words associated with reproduction, many parts of the human body, and sexual activity have been labeled bad.