'deal-maker' is a compound formed from 'deal' + 'maker'. 'deal' originates from Old English 'dǣl' (from Proto-Germanic '*dāliją') meaning 'part, portion' and later developed senses related to 'transaction'; 'maker' derives from Old English 'macere'/'macian' (verb) meaning 'to make'.

'deal' changed from Old English 'dǣl' meaning 'part, portion' and in Middle English acquired senses such as 'business transaction'; 'make' from Old English 'macian' produced agent nouns like 'maker'; the modern compound 'deal-maker' arose in modern English to denote someone who makes deals.

Initially, 'deal' meant 'part' or 'portion', but over time it developed the sense 'business transaction'; consequently, 'deal-maker' evolved to mean 'one who arranges or closes transactions/agreements'.