Smarmy

wiktionary

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smarm +‎  -y [en 1] Apparently coined by "B.R.L., of Brighton" with sense "saying treacly things which do not sound genuine" in a competition for neologisms in The Academy (London) published on 14 January 1899. [en 2]

etymonline

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smarmy (adj.)

"smooth and sleek" (1909); "ingratiating, unctuous," 1924, from smarm + -y (2). Related: Smarmily; smarminess.