'outfitter' originates from English, specifically the word 'outfit', where the prefix 'out-' meant 'outside' or 'beyond' and 'fit' meant 'to make ready'; the agentive suffix '-er' was then added to form the noun meaning 'one who outfits'.

'outfit' formed in Early Modern English from the combination of 'out-' + 'fit' (a verb meaning 'to make fit' or 'prepare'); over time 'outfit' developed both noun and verb senses. The agent noun 'outfitter' was formed from this base and came into use to refer to a person or business providing outfits/equipment.

Initially related forms meant 'to make fit' or 'to equip'; over time the derived noun 'outfitter' came to mean specifically 'a person or business that supplies equipment', focusing on the provider rather than the action.