A person who gibes; someone who mocks, taunts, or jeers at others.
From gibe + -er (agent noun suffix). This formation follows the standard English pattern of creating 'someone who does X' by adding -er to a verb.
History is full of famous gibers—court jesters, comedians, and satirists who made careers out of mocking power. Shakespeare's Feste and Touchstone were both professional gibers!
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