good turn(n = noun.act) turn - a favor for someone; "he did me a good turn"

N  good, benefit, advantage, improvement, greatest good, supreme good, interest, service, behoof, behalf, weal, main chance, summum bonum, common weal, consummation devoutly to be wished, gain, boot, profit, harvest, boon, good turn, blessing, world of good, piece of good luck, piece of good fortune, nuts, prize, windfall, godsend, waif, treasure-trove, good fortune, happiness, goodness, utility, remedy, pleasure giving, commendable, useful, good, beneficial, well, aright, satisfactorily, favorably, not amis, all for the best, to one's advantage, in one's favor, in one's interest, so far so good, magnum bonum.