turn off is a verb meaning "cause to stop operating by disengaging a switch". It carries 3 recorded senses.
cause to stop operating by disengaging a switch
“Turn off the stereo, please”
“cut the engine”
“turn out the lights”
Definitions, synonyms and semantic relations for turn off come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.