hueco
/ˈw̝eko/ · B1 · adj
hollow, empty
🕳️ hueco sounds like WAY-co: a gap in the wall is a way through
A hueco is a hole or empty space, like un hueco en la pared (a hole in the wall). As an adjective it means hollow: un árbol hueco is a hollow tree. In some countries it is also slang for gay or for someone clueless.