pylorus (n.)

1823, "gateway to an Egyptian temple," from Greek pylon "gateway," from pylē "gate, wing of a pair of double gates; an entrance, entrance into a country; mountain pass; narrow strait of water," a word of unknown etymology, perhaps a foreign technical term. The usual word for "door" in PIE in Greek took the form thyra (see thyroid). Meaning "tower for guiding aviators" (1909) led to that of "steel tower for high-tension wires" (1923).

Proto-Indo-European root meaning "perceive, watch out for."

It forms all or part of: Arcturus; avant-garde; award; aware; beware; Edward; ephor; garderobe; guard; hardware; irreverence; lord; panorama; pylorus; rearward; regard; revere; reverence; reverend; reward; software; steward; vanguard; ward; warden; warder; wardrobe; ware (n.) "manufactured goods, goods for sale;" ware (v.) "to take heed of, beware;" warehouse; wary.

It is the hypothetical source of/evidence for its existence is provided by: Latin vereri "to observe with awe, revere, respect, fear;" Greek ouros "a guard, watchman," horan "to see;" Hittite werite- "to see;" Old English weard "a guarding, protection; watchman, sentry, keeper."