not enough room to swing a cat

Noun

informal uncountable

(informal) Very little space (available) (of a very small room).

Japanese Meaning

非常に狭い空間；身動きの取れないほど狭い部屋 / 極端に狭く、利用可能なスペースがほとんどない状況

The tiny studio felt even smaller when three of us tried to fit in it — there was not enough room to swing a cat.

３人で押し入ろうとすると、その小さなワンルームはさらに狭く感じられ、猫を振り回す余地もないほどだった。

Sense（1）

(informal) Very little space (available) (of a very small room).

They had not space enough (according to the vulgar saying) to swing a Cat in.