Old English hydan (transitive and intransitive) "to hide, conceal; preserve; hide oneself; bury a corpse," from West Germanic *hudjan (source also of Middle Dutch, Middle Low German huden), from suffixed form of PIE *keudh- (source also of Greek keuthein "to hide, conceal"), from root *(s)keu- "to cover, conceal."
late Old English aweg, earlier on weg "on from this (that) place;" see a- (1) + way (n.).
Meaning "from one's own or accustomed place" is from c. 1300; that of "from one state or condition to another" is from mid-14c.; that of "from one's possession (give away, throw away) is from c. 1400. Colloquial use for "without delay" (fire away, also right away) is from earlier sense of "onward in time" (16c.). Meaning "at such a distance" (a mile away) is by 1712. Intensive use (as in away back) is American English, attested by 1818. Of sporting events played at the other team's field or court, by 1893.