From WordNet (r) 2.0 (August 2003) [wn]:
fool
n 1: a person who lacks good judgment [syn: sap, saphead,
muggins, tomfool]
2: a person who is gullible and easy to take advantage of [syn:
chump, gull, mark, patsy, fall guy, sucker,
soft touch, mug]
3: a professional clown employed to entertain a king or
nobleman in the middle ages [syn: jester, motley fool]
v 1: make a fool or dupe of [syn: gull, befool]
2: spend frivolously and unwisely; "Fritter away one's
inheritance" [syn: fritter, frivol away, dissipate,
shoot, fritter away, fool away]
3: fool or hoax; "The immigrant was duped because he trusted
everyone"; "You can't fool me!" [syn: gull, dupe,
slang, befool, cod, put on, take in, {put one
over}, put one across]
4: indulge in horseplay; "Enough horsing around--let's get back
to work!"; "The bored children were fooling about" [syn:
horse around, arse around, fool around]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Fool \Fool\, n. [Cf. F. fouler to tread, crush. Cf. 1st Foil.]
A compound of gooseberries scalded and crushed, with cream;
-- commonly called gooseberry fool.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Fool \Fool\, n. [OE. fol, n. & adj., F. fol, fou, foolish, mad;
a fool, prob. fr. L. follis a bellows, wind bag, an inflated
ball; perh. akin to E. bellows. Cf. Folly, Follicle.]
1. One destitute of reason, or of the common powers of
understanding; an idiot; a natural.
[1913 Webster]
2. A person deficient in intellect; one who acts absurdly, or
pursues a course contrary to the dictates of wisdom; one
without judgment; a simpleton; a dolt.
[1913 Webster]
Extol not riches, then, the toil of fools. --Milton.
[1913 Webster]
Experience keeps a dear school, but fools will learn
in no other. --Franklin.
[1913 Webster]
3. (Script.) One who acts contrary to moral and religious
wisdom; a wicked person.
[1913 Webster]
The fool hath said in his heart, There is no God.
--Ps. xiv. 1.
[1913 Webster]
4. One who counterfeits folly; a professional jester or
buffoon; a retainer formerly kept to make sport, dressed
fantastically in motley, with ridiculous accouterments.
[1913 Webster]
Can they think me . . . their fool or jester?
--Milton.
[1913 Webster]
April fool, Court fool, etc. See under April, Court,
etc.
Fool's cap, a cap or hood to which bells were usually
attached, formerly worn by professional jesters.
Fool's errand, an unreasonable, silly, profitless adventure
or undertaking.
Fool's gold, iron or copper pyrites, resembling gold in
color.
Fool's paradise, a name applied to a limbo (see under
Limbo) popularly believed to be the region of vanity and
nonsense. Hence, any foolish pleasure or condition of vain
self-satistaction.
Fool's parsley (Bot.), an annual umbelliferous plant
(Aethusa Cynapium) resembling parsley, but nauseous and
poisonous.
To make a fool of, to render ridiculous; to outwit; to
shame. [Colloq.]
To play the fool, to act foolishly; to act the buffoon; to
act a foolish part. "I have played the fool, and have
erred exceedingly." --1 Sam. xxvi. 21.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Fool \Fool\, v. i. [imp. & p. p. Fooled; p. pr. & vb. n.
Fooling.]
To play the fool.
[1913 Webster]
2. To waste time in unproductive activity; to spend time in
idle sport or mirth; to trifle; to toy.
Syn: fool around.
[PJC]
Is this a time for fooling? --Dryden.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Fool \Fool\, v. t.
1. To infatuate; to make foolish. --Shak.
[1913 Webster]
For, fooled with hope, men favor the deceit.
--Dryden.
[1913 Webster]
2. To use as a fool; to deceive in a shameful or mortifying
manner; to impose upon; to cheat by inspiring foolish
confidence; as, to fool one out of his money.
[1913 Webster]
You are fooled, discarded, and shook off
By him for whom these shames ye underwent. --Shak.
[1913 Webster]
To fool away, to get rid of foolishly; to spend in trifles,
idleness, folly, or without advantage.
[1913 Webster]
From The Free On-line Dictionary of Computing (19 Sep 2003) [foldoc]:
FOOL
Fool's Lisp. A small Scheme interpreter.
{(ftp://scam.berkeley.edu/src/local/fools.tar.Z)}
(1994-10-04)
From Jargon File (4.4.4, 14 Aug 2003) [jargon]:
fool
n.
As used by hackers, specifically describes a person who habitually
reasons from obviously or demonstrably incorrect premises and cannot
be persuaded by evidence to do otherwise; it is not generally used in
its other senses, i.e., to describe a person with a native incapacity
to reason correctly, or a clown. Indeed, in hackish experience many
fools are capable of reasoning all too effectively in executing their
errors. See also cretin, loser, fool file.
The Algol 68-R compiler used to initialize its storage to the
character string "F00LF00LF00LF00L..." because as a pointer or as a
floating point number it caused a crash, and as an integer or a
character string it was very recognizable in a dump. Sadly, one day a
very senior professor at Nottingham University wrote a program that
called him a fool. He proceeded to demonstrate the correctness of
this assertion by lobbying the university (not quite successfully) to
forbid the use of Algol on its computers. See also DEADBEEF.