'speech-impaired' originates from Modern English, specifically the compound of 'speech' and 'impaired'; 'speech' ultimately comes from Old English 'spæc' (meaning 'speech, talk'), and 'impaired' descends via Old French (e.g. 'empeirier'/'empirer') from Latin roots related to 'peior' (meaning 'worse').

'speech' changed from Old English 'spæc' to Middle English 'speche' and then to modern English 'speech'; 'impair' was borrowed via Old French ('empeirier'/'empirer') into Middle English (forms like 'impeiren'/'impeiren'), becoming modern 'impair' and yielding the past participle 'impaired'. The compound 'speech-impaired' was formed in modern English as a descriptive adjective.

Initially the components referred to 'speech' and the notion of being 'made worse'; over time the compound came to be used specifically to describe people who have a disorder or difficulty in producing spoken language, i.e., 'having difficulty speaking'.