noun
riding a tiger
Literary noun, almost exclusively used in the idiom 騎虎の勢い (きこのいきおい), meaning 'having no choice but to continue once started' (like riding a tiger and being unable to dismount).
See also: 騎虎の勢い
「騎虎の勢い」ということわざがある。
There is a proverb, 'riding a tiger's momentum' (meaning once you start, you cannot stop).