the.com/erection

means The hardening and rising of the penis (or clitoris) when spongy erectile tissue fills with blood, typically from arousal.

from From Latin erigere, 'to set up, raise upright' — built from e- ('out') plus regere ('to lead straight, direct, rule'), the same root that gives us 'regent' and 'correct.' For centuries 'erection' meant simply the act of building or raising something upright — a wall, a statue, a tent — and it's still used that way in architecture. The anatomical sense rode along on the same literal image of something going from flat to standing, and by the 16th–17th century it had taken on its specifically physiological meaning in English medical writing.