'atwirl' originates from English, formed from the prefix 'a-' plus the verb 'twirl'; the prefix 'a-' here comes from Old English 'on' or a- meaning 'in' or 'on', and 'twirl' meant 'to revolve or spin'.

'atwirl' developed from Middle English formations combining 'a-' with forms of 'twirl' (Middle English variants like 'twirlen'/'twerlen'), eventually stabilizing as the modern form 'atwirl'.

Initially it meant 'in a whirling or revolving manner', and this basic sense has largely remained, though the word is now rare or archaic in modern usage.