Source : Webster's Revised Unabridged Dictionary (1913)

Annotate \An"no*tate\, v. t. [imp. & p. p. {Annotated}; p. pr. &
   vb. n. {Annotating}.] [L. annotatus; p. p. of annotare to
   annotate; ad + notare to mark, nota mark. See {Note}, n.]
   To explain or criticize by notes; as, to annotate the works
   of Bacon.

Annotate \An"no*tate\, v. i.
   To make notes or comments; -- with on or upon.

Source : WordNet®

annotate
     v 1: add explanatory notes to or supply with critical comments;
          "The scholar annotated the early edition of a famous
          novel" [syn: {footnote}]
     2: provide interlinear explanations for words or phrases; "He
        annotated on what his teacher had written" [syn: {gloss},
        {comment}]

Source : Free On-Line Dictionary of Computing

annotate
     
        {annotation}