grace note

noun, Music.
1.
a note not essential to the harmony or melody, added as an embellishment, especially an appoggiatura.
Origin
1815-25
Examples from the web for grace note
  • The slight profile of her face adds the final grace note.
  • But it's a mistake to overlook this gem, an oasis that adds a grace note to a desolate, somewhat dicey area.
British Dictionary definitions for grace note

grace note

noun
1.
(music) a note printed in small type to indicate that it is melodically and harmonically nonessential