also: とじょう
noun
A place where gambling takes place, often illegal or underground.
警察が裏通りの賭場を摘発した。
The police raided a gambling den in the back alley.
彼は賭場で一晩中過ごした。
He spent the whole night at a gambling house.
カジノ is a general term for a casino, often legal and large-scale, while 賭場 implies a smaller, possibly illegal gambling place.
Compound of 賭 (to, 'gambling') and 場 (ba, 'place'). The reading とじょう uses the on'yomi of both characters.