out on a limb

Từ điển Oxford Advanced Learner 8th

out on a ˈlimb idiom
(informal)not supported by other people
•Are you prepared to go out on a limb (= risk doing sth that other people are not prepared to do) and make your suspicions public?
•His controversial stance has left him out on a limb.
Main entry: ↑limb_idiom