"the lime tree," 1570s, noun use of an adjective, "of linden wood," from Old English lind "linden" (n.), from Proto-Germanic *lindjo (cognates: Old Saxon linda, Old Norse lind, Old High German linta, German linde), probably from PIE *lent-o- "flexible" (see lithe); with reference to the tree's pliant bast. Compare Russian lutĭijó "forest of lime trees," Polish łęt "switch, twig," Lithuanian lenta "board, plank."