Synonyms and related words :
act of grace, act of kindness, benefaction, benefit, benevolence, benignity, blessing, complimentariness, costlessness, courtesy, expenselessness, favor, free ride, freebie, freeness, gift, good deed, good offices, good turn, grace, gratuitousness, gratuity, kind deed, kind offices, kindly act, kindness, mercy, mitzvah, no charge, obligation, office, service, turn