IPA: //ˈoʊvərˌsiːz//
KK: /ˈoʊvərˌsi/
In or to a foreign country, especially one across the sea.
Many students choose to study overseas for a year.
Oversea → It is formed from "over-" (meaning above or beyond) and "sea" (from Old English "sǣ", meaning large body of water). The word "oversea" refers to something that is beyond or across the sea.
Think of something that is 'beyond' ('over-') the 'sea' — that's why oversea means across the sea.