Also see definition of "Either" in Word Study
Either
EITHER [isbe]
EITHER - e'-ther, i'-ther: Often in the sense still common, "one or the other" (1 Ch 21:21; Mt 6:24, etc.), but also in the obsolete sense of "both" or "each" (Lev 10:1; 1 Ki 7:15; Jn 19:18; Rev 22:2), or in place of (Revised Version) "or" (Lk 6:42; 15:8; Phil 3:12; Jas 3:12).
Also see definition of "Either" in Word Study