Английский Этимологический словарь - by

- O.E. be (unstressed) or bi (stressed), from P.Gmc. *bi "around, about," from *umbi, from PIE *ambhi "around." Originally an adverbial particle of place, in which sense it is retained in place names (Whitby, Grimsby, etc.). Eliptical use for "secondary course" (opposed to main) was in O.E. Bygone is in M.E.; by-product is from 1857; bystander from 1619; bypass is 1848 of certain pipes in a gasworks, 1922 for "road for the relief of congestion." Phrase by and by (M.E.) originally meant "one by one," modern sense is from 1526.