(UK) A colloquial and mildly pejorative reaction to a clumsy or foolish action.

(rhetorical, often humorous or ironic) Used to announce a fact of which the addressee was, or appeared to be, ignorant.

(humorous) To be tone-deaf.

(idiomatic) To be responsible for someone's death, pain, or misfortune.

Alternative form of set one's heart on

What you now tell me is true I thought was false, or I nonetheless think is false; I don't believe you.

(idiomatic) To have good intentions.

To be at risk of sudden change; to be in an unstable state.

Said of a situation in which those in charge are incapable of handling their responsibilities, and should rather be put under scrutiny themselves.

To have another means or expedient kept in reserve in case the current one fails.