Name of a constellation (S/48) which is simply the word wilwarin “butterfly” used as a name (MC/223). It is unusual in that it begins with the letter [w], which in Quenya usually became [v], indicating it is probably of ancient origin. In one place (MR/166), Tolkien wrote this name as Vilvarin before changing it to Wilwarin. See the entry for vilvarin for further discussion.