From WordNet (r) 3.0 (2006) [wn]:
least
adv 1: used to form the superlative; "The garter snake is the
least dangerous snake" [syn: least, {to the lowest
degree}] [ant: most, to the highest degree]
adj 1: the superlative of `little' that can be used with mass
nouns and is usually preceded by `the'; a quantifier
meaning smallest in amount or extent or degree; "didn't
care the least bit"; "he has the least talent of anyone"
[ant: {most(a)}]
n 1: something that is of no importance; "it is the least I can
do"; "that is the least of my concerns"
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Least \Least\, adv.
In the smallest or lowest degree; in a degree below all
others; as, to reward those who least deserve it.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Least \Least\ (l[=e]st), a. [OE. last, lest, AS. l[=ae]sast,
l[=ae]sest, superl. of l[=ae]ssa less. See Less, a.] [Used
as the superlative of little.]
Smallest, either in size or degree; shortest; lowest; most
unimportant; as, the least insect; the least mercy; the least
space.
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Note: Least is often used with the, as if a noun.
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I am the least of the apostles. --1 Cor. xv.
9.
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At least, or At the least, at the least estimate,
consideration, chance, etc.; being no less than; hence, at
any rate; at all events; even. See However.
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He who tempts, though in vain, at least asperses
The tempted with dishonor. --Milton.
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Upon the mast they saw a young man, at least if he
were a man, who sat as on horseback. --Sir P.
Sidney.
In least, or In the least, in the least degree, manner,
etc. "He that is unjust in the least is unjust also in
much." --Luke xvi. 10.
Least squares (Math.), a method of deducing from a number
of carefully made yet slightly discordant observations of
a phenomenon the most probable values of the unknown
quantities.
Note: It takes as its fundamental principle that the most
probable values are those which make the sum of the
squares of the residual errors of the observation a
minimum.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Least \Least\, conj.
See Lest, conj. [Obs.] --Spenser.
[1913 Webster] Leastways