mid-15c., "duration, continuance" (a sense now obsolete; probably an abbreviated form of endurance); sense of "imprisonment, restraint of the person, involuntary confinement" is from 1510s, from Old French durance "duration," from durer "to endure," from Latin durare "to harden," from durus "hard," from PIE *dru-ro-, suffixed variant form of root *deru- "be firm, solid, steadfast."
