'haphazardly-combined' originates from the adverb 'haphazardly' (formed from 'haphazard' + the adverbial suffix '-ly') and the verb 'combine'. 'haphazard' itself comes from Middle English elements 'hap' (chance) and Old French 'hasard' (a game of chance), while 'combine' originates from Latin 'combinare'.

'haphazard' developed in Middle English by joining 'hap' (old word for chance) with 'hazard' (from Old French 'hasard'), and 'combine' passed from Latin 'combinare' into French 'combiner' before entering English; the hyphenated compound 'haphazardly-combined' is a modern English formation combining an adverb and a past participle to form a compound adjective.

Initially the component words referred to 'chance' ('haphazard') and 'joining together' ('combine'); over time the compound came to be used to describe things that are joined or assembled in a careless, random, or unplanned way.