other side
/ˌʌðəˈsʌɪd/noun
1With the. The enemy, the opposing side..
2With the. The afterlife; the spirit world, the abode of the dead.
3Chiefly Australian and NZ slang. Any place, especially a state or country, separated from the speaker by a border, sea, etc., or by a great distance.
Origin
Middle English (in an earlier sense). From other + side.