'asslike' originates from English, specifically formed from 'ass' (from Latin 'asinus' via Old English) and Old English 'lic' meaning 'like' or 'having the form of'.

'ass' comes from Old English 'assa' (from Latin 'asinus' meaning 'donkey'), and 'lic' (Old English) meaning 'like' combined in Middle English to produce forms such as 'asslic'/'asslike', eventually becoming the modern English 'asslike'.

Initially it meant 'having the form or qualities of a donkey'; over time it gained a figurative, derogatory sense meaning 'foolish' or 'stupid'.