adv. In the manner of an expletive. [ 1913 Webster ]

a. [ L. expletivus, from expletus, p. p. of explere to fill up; ex out+plere to fill, akin to plenus full: cf. F. explétif. See Full. ] Filling up; hence, added merely for the purpose of filling up; superfluous. “Expletive imagery.” Hallam. [ 1913 Webster ]

Expletive phrases to plump his speech. Barrow. [ 1913 Webster ]

n. A word, letter, or syllable not necessary to the sense, but inserted to fill a vacancy; an oath. [ 1913 Webster ]

While explectives their feeble aid to join,
And ten low words oft creep in one dull line. Pope. [ 1913 Webster ]