late 14c., from O.Fr. endurer, from L. indurare "make hard," in L.L. "harden (the heart) against," from in- "in" + durare "to harden," from durus "hard," from PIE *deru- "be firm, solid." Replaced the important O.E. verb dreogan (pt. dreag, pp. drogen), which survives in dial. dree. Related: Endured; endures.