torpor (n.)

Proto-Indo-European root meaning "stiff."

It forms all or part of: cholesterol; redstart; starch; stare; stark; stark-naked; start; startle; starve; stere; stereo-; stern (adj.); stork; strut; torpedo; torpid; torpor.

It is the hypothetical source of/evidence for its existence is provided by: Greek stereos "solid," sterizein "to support," sterphnios "stiff, rigid," sterphos "hide, skin;" Sanskrit sthirah "hard, firm," Persian suturg "strong;" Lithuanian storas "thick," strėgti "to become frozen;" Old Church Slavonic trupeti, Lithuanian tirpstu, tirpti "to become rigid;" Old Church Slavonic strublu "strong, hard," staru "old" (hence Russian stary "old"); Old English starian "to stare," stearc "stiff, strong, rigid," steorfan "to die," literally "become stiff," styrne "severe, strict."