snuff out is a verb meaning "put an end to; kill". It carries 2 recorded senses.
put an end to; kill
“The Nazis snuffed out the life of many Jewish children”
put out, as of fires, flames, or lights
“Too big to be extinguished at once, the forest fires at best could be contained”
“quench the flames”
“snuff out the candles”
Definitions, synonyms and semantic relations for snuff out come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.