By the way Synonyms, By the way Antonyms | Thesaurus.com

way O.E. weg "road, path, course of travel," from P.Gmc. *wegaz (cf. O.S., Du. weg, O.N. vegr, O.Fris. wei, O.H.G. weg, Ger. Weg, Goth. wigs "way"), from PIE *wegh- "to move" (see weigh). Most of the extended senses developed in M.E. Adj. meaning "very, extremely" is early 1980s, perhaps from phrase all the way. Wayfaring is O.E. wegfarende; Ways and means "resources at a person's disposal" is attested from c.1430. Way-out (adj.) "original, bold," is jazz slang, first recorded 1940s.

http://www.thesaurus.com/browse/by+the+way