"pertaining to two coasts," also bi-coastal, by 1977 in reference to the East and West coasts of the U.S. (or, specifically, New York and Los Angeles); from bi- + coastal.
Entries linking to bicoastal
bi-
word-forming element meaning "two, having two, twice, double, doubly, twofold, once every two," etc., from Latin bi- "twice, double," from Old Latin dvi- (cognate with Sanskrit dvi-, Greek di-, dis-, Old English twi-, German zwei- "twice, double"), from PIE root *dwo- "two."
Nativized from 16c. Occasionally bin- before vowels; this form originated in French, not Latin, and might be partly based on or influenced by Latin bini "twofold" (see binary). In chemical terms, it denotes two parts or equivalents of the substance referred to. Cognate with twi- and di- (1).
coastal adj.
"of or pertaining to a coast or shore," 1872, from coast (n.) + -al (1). The proper Latin form costal is used only of ribs.