The difference between Deceit and Dissimulation

When used as nouns, deceit means an act or practice intended to deceive, whereas dissimulation means the act of concealing the truth.

check bellow for the other definitions of Deceit and Dissimulation

Deceit as a noun:

An act or practice intended to deceive; a trick.

Examples:

"The whole conversation was merely a deceit."
Deceit as a noun:

An act of deceiving someone.
Deceit as a noun (uncountable):

The state of being deceitful or deceptive.
Deceit as a noun (legal):

The tort or fraudulent representation of a material fact made with knowledge of its falsity, or recklessly, or without reasonable grounds for believing its truth and with intent to induce reliance on it; the plaintiff justifiably relies on the deception, to his injury.

Dissimulation as a noun:

The act of concealing the truth; hypocrisy or deception.
Dissimulation as a noun:

Hiding one's feelings or intentions.