The word "mock" can be used as a verb or an adjective.
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Mock as a verb means to ridicule or belittle, often by imitation (e.g. mockingbird).
Example : "The students would mock the posture and the voice of the professor."
Mock as an adjective similarly means false, imitation, or phony (may include sarcasm).
Example : "Bill reacted with mock concern after his car nearly hit the neighbor's trash can."