Dissemble vs Nontruth - What's the difference?

As a verb dissemble

is to disguise or conceal something.

that which is not true; a lie or falsehood.

(dissembl)

To disguise or conceal something.

* Shakespeare

Dissemble all your griefs and discontents.

* J. P. Kemble

Perhaps it was right to dissemble your love.

To feign.

* 1681 , John Dryden,

And like a lion, slumb'ring in the way,

Or sleep-dissembling , while he waits his prey.

* Tatler

He soon dissembled a sleep.

To deliberately ignore something; to pretend not to notice.

To falsely hide one's opinions or feelings.

* XVII century, John Dryden, Cymon And Iphigenia''; from ''Boccace

While to his arms the blushing bride he took,

To seeming sadness she composed her look;

As if by force subjected to his will,

Though pleased, dissembling , and a woman still.

(en noun)

That which is not true; a lie or falsehood.