An Etymological Dictionary of Astronomy and Astrophysics

A person or a thing that is part of a group body; e.g. a star which belongs to a cluster.

Etymology (EN): From M.E., from O.Fr. membre, from L. membrum “limb, member of the body, part.”

Etymology (PE): Hamvand, literally “linked, joined together,” from ham- “together, with; same, equally, even” (Mid.Pers. ham-, like L. com- and Gk. syn- with neither of which it is cognate. O.Pers./Av. ham-, Skt. sam-; also O.Pers./Av. hama- “one and the same,” Skt. sama-, Gk. homos-; originally identical with PIE numeral *sam- “one,” from *som-. The Av. ham- appears in various forms: han- (before gutturals, palatals, dentals) and also hem-, hen-)

• vand “joined, tied,” from
  bastan, vastan “to bind, shut” (O.Pers./Av. band- “to bind, fetter,” banda- “band, tie” (cf.
  Skt. bandh- “to bind, tie, fasten;” PIE *bhendh- “to bind;” Ger. binden; E. bind).