A person who practices criticism; one devoted to critical analysis (rare or archaic term).
From critic plus -ist suffix meaning 'one who practices or is devoted to.' This appears occasionally in historical texts but is largely superseded by 'critic' or 'criticiser.'
'-ist' endings are usually reserved for ideologies ('communist,' 'feminist') or disciplines ('botanist,' 'physicist'), so 'criticist' sounds slightly awkward—probably why it lost out to the simpler 'critic.'
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