Etymon
gem-leusana-protogermanic-lausaz-protogermanic-lausaz-protowest-germanic-laus-old-english-leas-middle-english-les-english-less-english-tensionless-from-tension-less
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.