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).
late 14c., direccioun, "action of directing or guiding," from Latin directionem (nominative directio) "a making straight, a straight line, a directing (toward something)," noun of action from past-participle stem of dirigere "to set straight, arrange; give a particular direction to," from dis- "apart" (see dis-) + regere "to direct, to guide, keep straight" (from PIE root *reg- "move in a straight line").
Meaning "the act of governing, administration" is from early 15c. Sense of "relative position without regard to distance" is from 1660s. Meaning "course pursued by a moving object" is from 1660s.
Sense of "order, instruction in how to proceed" is from early 15c.; specific sense of "instruction in how to get somewhere" is from 1590s (directions in this sense is by 1749). Related: Directional.