Definition of expletives:
(n) :
A profane, vulgar term, notably a curse or obscene oath.
(n) :
An obscene or otherwise offensive interjection (such as shit, fuck, or damn it).
(n) :
(linguistics) A word that adds to the strength of a phrase without affecting its meaning (such as fuckin in "there's no fuckin way he's gonna get away with it").
(adj) :
Serving to fill up, merely for effect, otherwise redundant.
(adj) :
Marked by expletives (phrase-fillers).
(n) :
(linguistics) A word without meaning added to fill a syntactic position.