'coal-producing' originates from modern English as a compound of 'coal' and the present-participle form of 'produce'. 'Coal' ultimately comes from Old English 'col' (Old English) meaning 'coal', and 'produce' comes from Latin 'producere' via Middle English/Old French, where 'pro-' meant 'forth, forward' and 'ducere' meant 'to lead'.

'coal' developed from Old English 'col' into the modern English 'coal'; 'produce' came into English from Latin 'producere' through Old French and Middle English, and the present participle pattern produced adjectives like 'coal-producing' in modern English.

The components originally meant 'coal' and 'to lead forth/bring forth'; combined as a compound, the phrase has the straightforward meaning 'bringing forth or yielding coal', which has remained essentially literal in modern usage.