sap·ling \ˈsapliŋ, -lēŋ\noun (-s) Etymology: Middle English, from sap (I) + -ling 1.: a young tree; specifically: a young forest tree not over four inches in diameter at breast height 2.: youth < a young foolish sapling — Shakespeare > 3.: a greyhound whelped prior to a running season but in the same calendar year