'ashlar' originates from Old French, specifically the word 'eschier' (or similar medieval Norman forms), where the root is related to terms meaning 'to cut' or 'to carve'.

'ashlar' entered Middle English from Anglo-Norman/Old French (medieval forms such as 'ascler' or 'eschier') and evolved into the modern English form 'ashlar'.

Initially it referred to cut or carved stone (emphasizing the action of dressing the stone); over time it came to mean specifically a squared, finely dressed stone and the masonry built from such stones.