How do you spell Lest

Available Definitions:
1)  v. i. - To listen.
2)  n. - Lust; desire; pleasure.
3)  a. - Last; least.
4)  a. - For fear that; that . . . not; in order that . . . not.
5)  a. - That (without the negative particle); -- after certain expressions denoting fear or apprehension.