IPA: /ˈʌndəkrɒft/
KK: /ˈʌndərˌkrɔft/
A room or space located below ground level, often used for storage or as a burial place, especially beneath a church.
The ancient church had an undercroft that served as a burial site for its founders.
Undercroft → It is formed from "under" (from Old English "under", meaning beneath) and "croft" (from Old English "croft", meaning a small enclosed field or dwelling). The word "undercroft" refers to a space or room located beneath another structure, often used for storage or as a cellar.
Imagine a room that is 'beneath' ('under') another space, like a cellar or storage area — that's what an 'undercroft' is.
No commonly confused words.