at a venture

Etymology
From earlier, with the same meaning, from and.

Prepositional phrase

 * 1)  at random, without application of due thought, haphazardly or recklessly
 * 2) * 1780,, letter, 5 June:
 * For my own part, I never in my life began a letter more at a venture than the present.
 * For my own part, I never in my life began a letter more at a venture than the present.