'combustion-related' is a compound formed from the noun 'combustion' and the adjective 'related'. 'combustion' originates from Latin, specifically the word 'combustio' (from 'com-' + 'bustu-'/ 'būst-'), where elements conveyed the sense of burning; 'related' originates from Latin 'relatus' (past participle of 'referre').

'combustion' entered English via Late Latin/Medieval Latin 'combustio' meaning 'a burning' and became 'combustion' in Modern English; 'related' developed from Latin 'relatus' through Old French/Medieval English forms of 'relate' and eventually the adjectival use 'related' in Modern English. The compound 'combustion-related' is a modern English formation combining these elements.

Initially, 'combustion' meant 'a burning' in a literal sense; over time it has been used more broadly for chemical oxidation processes that produce heat and light. 'Related' originally indicated 'brought back' or 'referred' (from Latin roots) and evolved into the general sense 'connected to' used in the compound 'combustion-related'.