One who conquers; a person who defeats, overcomes, or subjugates others or obstacles.
From 'conquer' + '-er' (one who does), a standard English agentive suffix. Note this is an alternate spelling of 'conqueror,' with the 'e' retained from French.
The spelling 'conquerer' vs. 'conqueror' shows English's messy history with French loan words—both were used, but 'conqueror' eventually won out, showing how spelling standardization takes centuries.
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