'assort' originates from Old French, specifically the word 'assorter', which in turn comes from Vulgar Latin 'ad-sortire' (to distribute by lot); the components include Latin 'ad-' meaning 'to' and 'sors' (genitive 'sortis') meaning 'lot, fate, kind'.

'assort' changed from Old French 'assorter' into Middle English forms such as 'assorten' and eventually became the modern English word 'assort'; related noun 'assortment' was formed later in English.

Initially it implied distributing or allocating by lot ('to allot, assign'), but over time the meaning broadened to general arranging, classifying, or being of a similar kind ('to match').