'downfold' originates from Old English elements: 'down' (from Old English related forms meaning 'downwards') and 'fold' (from Old English 'fealdan'/'fold' meaning 'to bend or fold').

'downfold' was formed as a compound in Middle English from elements equivalent to 'down' + 'fold' (e.g. Middle English forms like 'doun' + 'folden' or similar compounds) and later produced the past/past-participle 'downfolded' in modern English.

Initially, the compound simply described the action 'fold down' (to fold toward or against a lower surface); over time it has remained consistent in meaning, also being used adjectivally as 'downfolded' to describe the state of having been folded down.