'ill-phrased' originates from English, combining the prefix 'ill' and the noun 'phrase', where 'ill' (from Old English 'ill') meant 'bad' or 'badly', and 'phrase' (from Greek 'phrasis' via Old French/Latin) meant 'a way of speaking or expressing'.

'phrase' changed from Greek word 'phrasis' to Latin/Old French 'phrase' and then into Middle English 'phrase', eventually becoming the modern English 'phrase'. The element 'ill' comes from Old English 'ill' and has remained largely similar in form and meaning into modern English.

Initially it combined the sense 'badly' + 'a way of expressing', and over time it evolved into the current adjectival meaning 'poorly expressed' (i.e., 'badly worded').