'annotate' originates from Latin, specifically the word 'annotare', where 'ad-' meant 'to' and 'notare' meant 'to mark' or 'to note'.

'annotate' came from the Latin 'annotare' (formed from 'ad-' + 'notare'), passed through Medieval Latin and later influenced English via the noun 'annotation' and related forms, becoming 'annotate' in modern English.

Initially it meant 'to make a note' or 'to mark down', and over time it evolved to its current sense of 'to add explanatory notes or comments' to a text.