lest

For fear that.

So that someone or something not; in case someone or something might.

For fear that; that … not; so that … not: as, he fled lest (or for fear that) he should be killed; take heed lest you fall (that you fall not).

etc. A Middle English form of last, least, list, lust.

To listen.

Lust; desire; pleasure.

Last; least.

For fear that; that … not; in order that … not.

That (without the negative particle); — after certain expressions denoting fear or apprehension.

For fear that; that . . . not; in order that . . . not; in case.