Entry 2 senses · 2 variants Webster, 1913 Expletive /ĕk'-splət-ĭv/ · Ex·ple·tive · IPA /ˈɛksplətɪv/ a. n. 01 a. Filling up; hence, added merely for the purpose of filling up; superfluous. 1. Filling up; hence, added merely for the purpose of filling up; superfluous. “Expletive phrases to plump his speech.” — Barrow. 02 n. A word, letter, or syllable not necessary to the sense, but inserted to fill a vacancy; an oath. 1. A word, letter, or syllable not necessary to the sense, but inserted to fill a vacancy; an oath. “While explectives their feeble aid to join, And ten low words oft creep in one dull line.” — Pope.