"lethargy, listlessness," c. 1600, from Latin torpor "numbness, sluggishness," from torpere "be numb, be inactive, be dull" (from PIE root *ster- (1) "stiff").
"state or quality of being inactive," 1630s, from Latin quiescentia, from quiescere "to rest" (from suffixed form of PIE root *kweie- "to rest, be quiet"). Related: Quiescency.
"dogfish, shark," a name given to various sharks of inactive habits, c. 1500, of unknown origin. Perhaps identical to nurse (n.1), but the sense is obscure, or perhaps a different word conformed to it by folk-etymology.
"inclined to sleep, sleepy," 1520s, probably ultimately from Old English drusan, drusian "sink," also "become languid, slow, or inactive" (related to dreosan "to fall;" see dreary). There is no record of it in Middle English. Related: Drowsily; drowsiness.