"Stub out" is a phrase mostly used in reference to cigarettes and refers to the act of extinguishing a cigarette by pressing the lit end against a surface until it stops burning. However, there are other terms that can be used interchangeably to convey the same meaning. Some of the synonyms for "stub out" include "butt out," "snuff out," "grind out," "trample out," "quash," "extinguish," and "suppress." Each of these synonymous terms can be used depending on the context and preference of the speaker. Regardless of which term is used, the underlying message is the same - the cigarette should be put out to prevent any risks of fire or unwanted odor.