Smooch

wiktionary

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Perhaps from a dialectal variation of smack. Compare also Low German smok(“a kiss, a smouch”).

smooch (third-person singular simple present smooches, present participle smooching, simple past and past participle smooched)

etymonline

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smooch (v.)

1932, alteration of dialectal verb smouch "to kiss" (1570s), possibly imitative of the sound of kissing (compare German dialectal schmutzen "to kiss"). An earlier alteration produced smudge (v.) "to kiss, caress" (1844). Related: Smooched; smooching. As a noun by 1942.