erect (adj.)

late 14c., "upright, not bending," from Latin erectus "upright, elevated, lofty; eager, alert, aroused; resolute; arrogant," past participle of erigere "raise or set up," from e- "up, out of" + regere "to direct, keep straight, guide" (from PIE root *reg- "move in a straight line," with derivatives meaning "to direct in a straight line," thus "to lead, rule").

erect (v.)

c. 1400, a back-formation from erect (adj.) or else from Latin erectus. Related: Erected; erecting.