The noun is attested since 1914, from the colloquial verb smalm, smarm (“to smear, bedaub (hair, with pomade)”), attested since 1847, of unknown origin, perhaps somehow suggestive of the action. Verbal meaning "to smear with flattery" is from 1902.
Meanings
(countable, uncountable) Smarmy language or behavior.
Phil Hartman, the voice and soul of McClure, was the king of making everything sounds cheerful and positive, no matter how grim. McClure was the personification of smarm. He alone could say, “Your children are missing. I know because I murdered them with my own hands!” and make it sound like good news. 2012 May 20, Nathan Rabin, “TV: Review: THE SIMPSONS (CLASSIC): “Marge Gets A Job” (season 4, episode 7; originally aired 11/05/1992)”, in The Onion AV Club:
(countable, slang, uncountable) A style of fan fiction in which characters are warm and caring toward each other but without sexual overtones.
The noun is attested since 1914, from the colloquial verb smalm, smarm (“to smear, bedaub (hair, with pomade)”), attested since 1847, of unknown origin, perhaps somehow suggestive of the action. Verbal meaning "to smear with flattery" is from 1902.
Meanings
(intransitive) To fawn, to be unctuous.
(transitive) To address in a fawning and unctuous manner.
"If you go to her and smarm her, it will be all right."
"If I do what to her?" asked Mervyn, wondering what the operation of smarming might be.
"Of course you don't know," laughed Aggie; "it is a school word. You explain what it means, Isabel."
"To smarm," explained Isabel, "signifies to say 'yes ma'am,' or 'yes marm,' to a governess when she is rating you. It is ah expressive word, isn't it? It means 'to conciliate by assent;' that is the best definition that I can give of it."
"Excellent word," said Mervyn. "Then. I am to smarm your mamma, am I, Aggie?["] 1874, Frank Usher, A strange love, volume 2, London: Tinsley Bros, page 53:
He rose ... on his wife's fortune and judicious smarming of powerful people. 1957, Lawrence Durrell, Justine: