from
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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