What does "lest" mean?

Lest: For Love not sleep, lest thou come to poverty. Prov. xx.

Additional senses

  1. 2.Wherefore let him that thinketh he standeth he standeth take heed lest he fall. I Cor. x.
  2. 3.2. That (without the negative particle); -- after certain expressions denoting fear or apprehension. I feared Lest I might anger thee. Shak.

Sources