Green’s Dictionary of Slang

to enjoy sexual preliminaries, stopping short of intercourse, usu. of teenage experimentation; 1980s+ use normally implies only French kissing; thus snogging n.

1945		C.H. Ward-Jackson It’s a Piece of Cake (2nd edn) 56: Snogging, courting, running around with the opposite sex. Comes from India. Thus, ‘On my leave I’m going up to the hills for a bit of snogging.’ Also used as a verb.
1959		K. Waterhouse Billy Liar (1962) 55: A dirty, crumpled bag of chocolates [...] I had bought them when Stamp handed over his white box of passion pills. ‘You’ll need snogging fodder to go with them,’ he explained.
1963		N. Dunn Up the Junction 14: You get a funny taste in your mouth after you’ve been snoggin’, don’t yer?
1970		A. Sillitoe Start in Life (1979) 23: A courting couple were snogging on the path in front.
1982		Maledicta VI:1+2 (Summer/Winter) 132: passion pit [...] usually means a cinema for necking, U.K. snogging.
1992		D. Jarman letter 2 Apr. Smiling in Slow Motion (2000) 110: We had a very happy dinnner, with Christine snogging her girlfriend to the surprise of the clientele.
2006		D. Mitchell Black Swan Green 42: The idea of any boy snogging my sister makes me grab the vomit bucket.
2010		K. Richards Life 75: We were just snogging [...] tongues going like eels.
2021		C. Hammer Opal Country 328: She and Topsoil snogging in the corner.