Pronunciation: (ek'spli-tiv), [key]
1. an interjectory word or expression, frequently profane; an exclamatory oath.
2. a syllable, word, or phrase serving to fill out.
3. Gram.a word considered as regularly filling the syntactic position of another, as it in It is his duty to go, or there in There is nothing here.
Also,ex•ple•to•ryPronunciation: (ek'spli-tôr"ē, -tōr"ē). [key]added merely to fill out a sentence or line, give emphasis, etc.: Expletive remarks padded the speech.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.