Deceit, duplicity, dissimulation, cunning, guile mean the quality, the habit, the act, or the practice of imposing upon the credulity of others by dishonesty, fraud, or trickery.
Deceit usually implies the intent to mislead or delude; otherwise, it is the most comprehensive of these terms, for it mayr imply deliberate misrepresentation or falsification, the assumption of a false appearance, the use of fraud or trickery or craft.
Duplicity commonly implies double-dealing or bad faith; usually it suggests a pretense of feeling one way and an acting under the influence of another and opposite feeling.
The word may sometimes imply no more than the appearance of deceit arising out of a complexity of motives or a lack of singlemindedness.
Dissimulation implies deceit by concealing what one truly is or what one actually feels and therefore often suggests duplicity.
Cunning implies deceit by the use of trickery, wiles, or stratagems; it often connotes a perverted intelligence and almost vicious shrewdness in attaining one’s end.
Guile carries an even stronger implication of lack of obviousness in the arts practiced or tricks used than does cunning; in strict use it carries a strong implication of insidiousness or treacherousness.
The word has, however, so long been used in such phrases as “without guile” and “devoid of guile” that it often is used in a very much weaker sense than cunning, sometimes implying little more than artfulness or the use of wiles.