IPA: /ˈbætəlˌɡraʊnd/
KK: /ˈbætəlˌɡraʊnd/
A place where a battle is fought, often used to refer to the area of conflict in a war or a competition.
The soldiers prepared for the fight on the battleground, knowing it would be a tough battle.
Battleground is formed from "battle" (from Old French *bataille*, meaning a fight or conflict) and "ground" (from Old English *grund*, meaning land or soil). The word refers to a place where battles are fought, specifically the land on which the conflict occurs.
Think of a 'fight' ('battle') taking place on a specific 'land' ('ground') — that's what a battleground is.
No commonly confused words.