belly of a boat; ship's bottom
Refers to the underside or bottom of a boat or ship. Can be used literally or figuratively.
A small hole opened in the belly of the boat.
Compound of 船 (ふね, 'boat') + の (possessive particle) + 腹 (はら, 'belly'). The figurative use of 'belly' for the underside of a vessel is common across languages.