noun
1. : a musical note constituting or being part of an ornament ; especially : appoggiatura , acciaccatura
2. : something resembling or suggesting a grace note in forming a very small decorative unessential part of or addition to some large whole
the literary contributions made by the President's collaborators … merely added grace notes to compositions that were the President's own — New Yorker
the chanted songs … seem to have no real organic connection with the central theme but to be merely arbitrary and distracting grace notes — Wolcott Gibbs