An Etymological Dictionary of Astronomy and Astrophysics

A company of persons gathered for a common reason, as for deliberation,
legislation, worship, or entertainment.
The act of assembling; the state of being assembled.

Etymology (EN): M.E. assemblee, from M.Fr., from O.Fr., from assembler “to gather together.”

Etymology (PE): Hamâyeš, from ham- “together,” → com- + âyeš “coming,” from ây- present stem of
âmadan “to come;” O.Pers. aitiy “goes;” Av. ay- “to go, to come,” aēiti “goes;” cf. Skt. e- “to come near,” eti “arrival;” Gk. eimi “I go,” L. ire “to go, walk,” eo “I go;” Tokharian AB i-; PIE *ei- “to go, to walk.”