PIE base ‘to perceive, watch out for’. See also *weid- ‘to see, know’, root of vision, and *spek- ‘to observe’, root of species and specialist.
Other derivatives include aware, revere, regard, wary, ward, warden, steward, lord, reward, guard, software, and panorama.
[Pokorny u̯er-8, ‘to notice, observe, attend, be aware’, p. 1164.]