A course of action which invites risk; a perilous or audacious undertaking the outcome of which is unknown; a daring feat or exploit. Later also…

An act or occasion of trying one's chance or fortune; a course or proceeding the outcome of which is uncertain, but which is attended by the risk…

An adventure; an enterprise or undertaking.

A hazardous journey, undertaking, or course of action; a venture. Obsolete.

A shift or effort which one makes for oneself. to make a fend: to make a venture.

A perilous or desperate enterprise.

an unlikely chance; (also) a chance involving great risk.

a daring or flying leap (as of a trapeze artist, etc.); also figurative, a step that involves risk; an unjustified inference, a ‘leap of faith’.

figurative. A situation or undertaking regarded as uncertain, risky, or unpredictable.