Etymon
gem-an-protowest-germanic-ana-old-english-on-middle-english-an-middle-english-a-english-a-protoindoeuropean-kwel-protoindoeuropean-kwekwleh2-protogermanic-hweulo-old-english-hweol-middle-english-whel-english-wheel-english-awheel-from-a-wheel
A dedicated page for this root is on the way — it will gather every word descended from it, sibling forms across daughter languages, and a branching map of the family tree.