'life-supporting' originates from Modern English, formed by combining the noun 'life' and the present participle 'supporting' (from the verb 'support'). 'Life' comes from Old English 'līf' meaning 'life, being', and 'support' ultimately traces to Latin 'supportare' (from 'sub-' meaning 'under' + 'portare' meaning 'to carry').

'life' developed from Old English 'līf' (from Proto-Germanic *libam). 'Support' entered English via Old French (e.g. 'soutenir'/'souporter') from Latin 'supportare'; Middle English forms like 'supporten' gave the modern verb 'support', and combining 'life' + present participle 'supporting' produced the compound adjective 'life-supporting' in modern usage.

Initially, the separate words meant 'existence' ('life') and 'to carry from below/assist' ('support'); over time the compound came to mean 'able to sustain life' or 'providing conditions for life' in its current sense.