Sapling comes from Middle English, formed from sap + the diminutive suffix -ling, the young tree being conceived as full of sap; sap is from Old English sæp. The historical chain includes Old English sæp and Proto-Germanic *sapą. The formation is best read as suffixal, compound, and borrowed: the word sapling carries its older form-history into a compact English lexical shape. In present English it is used as a noun, "a young, slender tree". Related English forms include sap, sappy, and sapful. The result is a noun whose etymology preserves both the older form and the later English specialization.