The Collaborative International Dictionary of English v.0.48:

Lest \Lest\ (l[e^]st), v. i.
   To listen. [Obs.] --Chaucer. Spenser.
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The Collaborative International Dictionary of English v.0.48:

Lest \Lest\, n. [See List to choose.]
   Lust; desire; pleasure. [Obs.] --Chaucer.
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The Collaborative International Dictionary of English v.0.48:

Lest \Lest\, a.
   Last; least. [Obs.] --Chaucer.
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The Collaborative International Dictionary of English v.0.48:

Lest \Lest\, conj. [OE. leste, fr. AS. [eth][=y] l[=ae]s
   [eth][=e] the less that, where [eth][=y] is the instrumental
   case of the definite article, and [eth][=e] is an
   indeclinable relative particle, that, who, which. See The,
   Less, a.]
   1. For fear that; that . . . not; in order that . . . not.
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            Love not sleep, lest thou come to poverty. --Prov.
                                                  xx. 13.
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            Wherefore let him that thinketh he standeth take
            heed lest he fall.                    --1 Cor. x.
                                                  12.
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   2. That (without the negative particle); -- after certain
      expressions denoting fear or apprehension.
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            I feared
            Lest I might anger thee.              --Shak.
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