Deceit, n.
Etymology: [OF. deceit, des, decept (cf. deceite, de), fr. L. deceptus deception, fr. decipere. See Deceive.]
1. An attempt or disposition to deceive or lead into error; any declaration, artifice, or practice, which misleads another, or causes him to believe what is false; a contrivance to entrap; deception; a wily device; fraud. Making the ephah small and the shekel great, and falsifying the balances by deceit. Amos viii. 5. Friendly to man, far from deceit or guile. Milton. Yet still we hug the dear deceit. N. Cotton.
2. (Law)
Any trick, collusion, contrivance, false representation, or underhand practice, used to defraud another. When injury is thereby effected, an action of deceit, as it called, lies for compensation.
Syn. -- Deception; fraud; imposition; duplicity; trickery; guile; falsifying; double-dealing; stratagem. See Deception.
Shades of meaning
Fernald has no entry of its own for deceit; he lists it under deception, fraud.
Where he writes about it:
Deceit is the habit, deception the act; guile applies to the disposition out of which deceit and deception grow, and also to their actual practise. — from deception
Falsehood and lying are in utterance; deceit and deception may be merely in act or implication. — from deception
Deception may be innocent, and even unintentional, as in the case of an optical illusion; deceit always involves injurious intent. — from deception
Finesse is simply an adroit and delicate management of a matter for one's own side, not necessarily involving deceit. — from deception
A deceit or deception may be designed merely to gain some end of one's own, with no intent of harming another; an imposition, to take some small advantage of another, or simply to make another ridiculous. — from fraud
Fraud includes deceit, but deceit may not reach the gravity of fraud; a cheat is of the nature of fraud, but of a petty sort; a swindle is more serious than a cheat, involving larger values and more flagrant dishonesty. — from fraud