Origin: Germanic Old English prefix
Overseas has 6 different meanings across 2 categories:
Abroad.
"She decided to spend her summer vacation overseas instead of staying home."
In plain English: Overseas means something that is located on a different continent across the ocean from where you live.
"The overseas branch of the company opened its new office yesterday."
Usage: Use overseas only to describe something or someone located in a foreign country, typically across an ocean from the speaker's location. Do not use it as a noun; instead, say "an overseas worker" rather than "the overseas."
Abroad.
"We are planning to spend our summer vacation overseas visiting my grandmother in Italy."
In plain English: Overseas means going to a country on a different continent across the ocean.
"Many students choose to study overseas for their degrees."
Usage: Use "overseas" as an adverb to describe actions or locations that are in foreign countries across the sea, such as traveling overseas or living overseas. It functions without needing a following noun because it inherently means abroad.
Overseas comes from the older word oversea combined with the suffix -s. The term entered English by adding a plural marker to describe lands across the sea, similar to related words in West Frisian, Dutch, and German.