'misassociate' originates from the English prefix 'mis-' (Old English) meaning 'wrongly' combined with 'associate', ultimately from Latin 'associare' (from 'ad-' + 'sociāre'), where 'sociāre' meant 'to join' and 'socius' meant 'companion'.

'associate' changed from Latin 'associare' into Old French forms and then into Middle English (e.g. 'associaten') before becoming modern English 'associate'; the English prefix 'mis-' was later attached to form 'misassociate' meaning to associate wrongly.

Initially 'associate' meant 'to join or connect'; with the addition of the prefix 'mis-' the compound came to mean 'to connect or attribute incorrectly', shifting the sense to an incorrect linking.