Estray comes from Anglo-Norman estray, from Old French estraier 'to wander, roam', from Vulgar Latin *extravagare 'to wander outside', from Latin extra 'beyond' + vagari 'to wander'. Morphologically, the form is compositional, with the named elements combining to produce the modern spelling and sense. In present use, it is used as a noun meaning "a domestic animal found wandering with no apparent owner", so the historical material remains connected with the current sense rather than standing as bare ancestry. The wider English family includes related forms such as stray, astray, and estrange, showing how the same historical material continues to organize neighboring vocabulary. The named historical forms include Old French estraier, Latin *extravagare, and Latin vagari, keeping the history tied to concrete forms rather than a loose resemblance. Its semantic neighborhood includes stray and waif, locating the modern specialization without adding a new origin story.