Boy's play

childish amusements; anything trifling.

See also: Boy

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in classic literature ?
Man does some of his part of the exchange work in his six weeks of haying, and it is no boy's play. Certainly no nation that lived simply in all respects, that is, no nation of philosophers, would commit so great a blunder as to use the labor of animals.
She was fond of all boy's plays, and greatly preferred cricket not merely to dolls, but to the more heroic enjoyments of infancy, nursing a dormouse, feeding a canary-bird, or watering a rose-bush.
Paolo Barro shot a two-over-par 74 on Wednesday to take a five-shot lead in boy's play even as Kayla Nocum shot a 69 and moved past Junia Gabasa halfway through the Philippine Junior Amateur Open Golf Championships at Sherwood Hills Golf Club in Trece Martires, Cavite.