The Collaborative International Dictionary of English v.0.48:
Let \Let\, v. t. [imp. & p. p. Let (Letted (l[e^]t"t[e^]d),
[Obs].); p. pr. & vb. n. Letting.] [OE. leten, l[ae]ten
(past tense lat, let, p. p. laten, leten, lete), AS.
l[=ae]tan (past tense l[=e]t, p. p. l[=ae]ten); akin to
OFries. l[=e]ta, OS. l[=a]tan, D. laten, G. lassen, OHG.
l[=a]zzan, Icel. l[=a]ta, Sw. l[*a]ta, Dan. lade, Goth.
l[=e]tan, and L. lassus weary. The original meaning seems to
have been, to let loose, let go, let drop. Cf. Alas,
Late, Lassitude, Let to hinder.]
1. To leave; to relinquish; to abandon. [Obs. or Archaic,
except when followed by alone or be.]
He . . . prayed him his voyage for to let.
Yet neither spins nor cards, ne cares nor frets,
But to her mother Nature all her care she lets.
Let me alone in choosing of my wife. --Chaucer.
2. To consider; to think; to esteem. [Obs.] --Chaucer.
3. To cause; to make; -- used with the infinitive in the
active form but in the passive sense; as, let make, i. e.,
cause to be made; let bring, i. e., cause to be brought.
This irous, cursed wretch
Let this knight's son anon before him fetch.
He . . . thus let do slay hem all three. --Chaucer.
Anon he let two coffers make. --Gower.
4. To permit; to allow; to suffer; -- either affirmatively,
by positive act, or negatively, by neglecting to restrain
Note: In this sense, when followed by an infinitive, the
latter is commonly without the sign to; as to let us
walk, i. e., to permit or suffer us to walk. Sometimes
there is entire omission of the verb; as, to let [to be
or to go] loose.
Pharaoh said, I will let you go. --Ex. viii.
If your name be Horatio, as I am let to know it
5. To allow to be used or occupied for a compensation; to
lease; to rent; to hire out; -- often with out; as, to let
a farm; to let a house; to let out horses.
6. To give, grant, or assign, as a work, privilege, or
contract; -- often with out; as, to let the building of a
bridge; to let out the lathing and the plastering.
Note: The active form of the infinitive of let, as of many
other English verbs, is often used in a passive sense;
as, a house to let (i. e., for letting, or to be let).
This form of expression conforms to the use of the
Anglo-Saxon gerund with to (dative infinitive) which
was commonly so employed. See Gerund, 2. " Your
elegant house in Harley Street is to let." --Thackeray.
In the imperative mood, before the first person plural,
let has a hortative force. " Rise up, let us go."
--Mark xiv. 42. " Let us seek out some desolate shade."
To let alone, to leave; to withdraw from; to refrain from
To let blood, to cause blood to flow; to bleed.
To let down.
(a) To lower.
(b) To soften in tempering; as, to let down tools,
cutlery, and the like.
To let fly or To let drive, to discharge with violence,
as a blow, an arrow, or stone. See under Drive, and
To let in or To let into.
(a) To permit or suffer to enter; to admit.
(b) To insert, or imbed, as a piece of wood, in a recess
formed in a surface for the purpose.
To let loose, to remove restraint from; to permit to wander
To let off.
(a) To discharge; to let fly, as an arrow; to fire the
charge of, as a gun.
(b) To release, as from an engagement or obligation.
To let out.
(a) To allow to go forth; as, to let out a prisoner.
(b) To extend or loosen, as the folds of a garment; to
enlarge; to suffer to run out, as a cord.
(c) To lease; to give out for performance by contract, as
(d) To divulge.
To let slide, to let go; to cease to care for. [Colloq.] "
Let the world slide." --Shak.