Source : WordNet®

incidentally
     adv 1: introducing a different topic; "by the way, I won't go to
            the party" [syn: {by the way}, {by the bye}]
     2: in an incidental manner; "these magnificent achievements
        were only incidentally influenced by Oriental models"
        [syn: {accidentally}, {by chance}]
     3: by the way; "apropos, can you lend me some money for the
        weekend?" [syn: {apropos}]