comment: [15] In Latin, a commentum was originally ‘something invented or devised’. It was derived from the verb comminiscī ‘devise, contrive by thought’, a compound formed from the prefix com- ‘with’ and a base *men- (this also produced Latin mens and mentiō, source respectively of English mental and mention). It was used in the 7th century by the Spanish theologian Isidore in the sense ‘interpretation, annotation’, and it was with that meaning rather than the original ‘contrivance’ that the word passed eventually into English. => mental, mention, mind
