late 12c., "God's favor or help," from Old French grace "pardon, divine grace, mercy; favor, thanks; elegance, virtue" (12c.), from Latin gratia "favor, esteem, regard; pleasing quality, good will, gratitude" (source of Italian grazia, Spanish gracia), from gratus "pleasing, agreeable," from PIE root *gwere- (3) "to favor" (cognates: Sanskrit grnati "sings, praises, announces," Lithuanian giriu "to praise, celebrate," Avestan gar- "to praise").Sense of "virtue" is early 14c., that of "beauty of form or movement, pleasing quality" is mid-14c. In classical sense, "one of the three sister goddesses (Latin Gratiæ, Greek Kharites), bestowers of beauty and charm," it is first recorded in English 1579 in Spenser. The short prayer that is said before or after a meal (early 13c.; until 16c. usually graces) has a sense of "gratitude."

c.1200, "to thank," from Old French gracier, from grace (see grace, n.). Meaning "to show favor" (mid-15c.) led to that of "to lend or add grace to something" (1580s, as in grace us with your presence), which is the root of the musical sense in grace notes (1650s). Related: Graced; gracing.