annotation
Concise Oxford English Dictionary © 2008 Oxford University Press:
annotate /ˈanəteɪt/
▶verb add notes to (a text or diagram) giving explanation or comment.
– derivatives
annotatable adjective,
annotation noun,
annotative adjective,
annotator noun.
annotatable adjective,
annotation noun,
annotative adjective,
annotator noun.
– origin C16 (earlier (ME) as annotation): from L. annotat-, annotare ‘mark’.
'annotation' also found in these Oxford entries:

