From PIE *per- (forward, through, beyond) — the same root behind 'for,' 'fore,' 'first,' 'from,' 'forth,' and 'further.'
At, to, or by a great distance in space or time; a long way off.
From Old English 'feorr' (far, remote, distant), from Proto-Germanic *ferrai (far), from PIE root *per- (forward, through, across, beyond). This PIE root is among the most productive in the entire language family, generating an enormous web of English descendants: 'far,' 'for,' 'fore,' 'first,' 'from,' 'forth,' 'further,' 'before,' 'former,' and 'foremost' all trace to the same ancient notion of forward motion and spatial extension. The same root produced Latin 'per' (through), 'prae' (before), 'prīmus' (first), and 'prō' (forward); Greek 'pérā' (beyond), 'pró' (before), and 'prótos' (first); and
The PIE root *per- (forward, beyond) that gave English 'far' is also the ancestor of 'for,' 'fore,' 'first,' 'from,' 'forth,' 'further,' 'para-,' 'per-,' 'pro-,' and 'pre-' — making it one of the most productive roots in English. Nearly every common preposition and prefix denoting forward motion or distance traces back to this single ancient syllable.