intransitive. To draw back, withdraw, or distance oneself from an undertaking, declaration, course of action, opinion, etc.

to back out: to move backward out of a place without turning; figurative to draw back cautiously or tacitly from an arrangement or situation, to…

intransitive. Scottish and English regional (northern). To change one's mind, withdraw, or back out from a venture or undertaking; to ‘chicken out’…

To back out, withdraw; to make off, abscond; to default. colloquial (originally U.S.).

intransitive. U.S. slang. With out. To display cowardice; to back out from cowardice; (hence) to withdraw one's support, to quit.

With on: to betray or let down (someone). Also without const., to funk, to behave in a cowardly manner; to wriggle or squirm. Australian slang.

intransitive. Frequently with out. To lose one's nerve and decide not to do something; to back out.

To escape from or extricate oneself out (of a situation, obligation, etc.), esp. dishonourably; to welsh on. Also with one's way.

intransitive. to wuss out: to avoid an action or withdraw from a commitment, as a result of perceived cowardice or weakness. Cf. wimp, v.