How many syllables in expletive?

Definition of expletive:

expletive (noun):

profane or obscene expression usually of surprise or anger.

an exclamation or swearword expressing emotion rather than meaning

a syllable, word, or phrase inserted to fill a vacancy (as in a sentence or a metrical line) without adding to the sense

a word (such as it in "make it clear which you prefer") that occupies the position of the subject or object of a verb in normal english word order and anticipates a subsequent word or phrase that supplies the needed meaningful content