biangular (adj.)

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).

1590s, "having an angle or angles, pointy," from Latin angularis "having corners or angles," from angulus "angle, corner" (see angle (n.)). It is attested earlier in an astrological sense, "occupying a cardinal point of the zodiac" (late 14c.). Angulous "having many corners" is from mid-15c. Angular as "measured by an angle" is from 1670s, hence angular motion "motion of a body which moves around a fixed point."