'unavowed' is a correct and usable word in written English.
You can use it to refer to something that has been kept secret, or that has not been acknowledged, stated, or admitted. For example: "The politician refused to acknowledge his unavowed children."
But it must be borne in mind that laughter is a phenomenon of the trigger-releaser type, where a sudden turn of the tap may release vast amounts of stored emotions, derived from various, often unconscious, sources: repressed sadism, sexual tumescence, unavowed fear, even boredom.
In Bergson's view, laughter is the corrective punishment inflicted by society upon the unsocial individual: "In laughter we always find an unavowed intention to humiliate and consequently to correct our neighbour".
On the whole, however, there was an unavowed truce between Christianity and paganism, only occasionally broken, as when Julian revived a range of pagan types; the full development of the Christian tradition in coinage was reserved for Byzantium.
Although an unavowed Catholic, he wished only open toleration for English Catholics and ardently favoured the accession of James I after the Scottish king had given assurances on the question.
Other Democratic candidates, avowed or unavowed, included Sen. Lyndon B. Johnson of Texas, the Democratic leader in the Senate; Sen. Stuart W. Symington of Missouri, former secretary of the air force; and Adlai E. Stevenson, former governor of Illinois, who had been the Democratic nominee in 1952 and 1956.
In an atmosphere heavy with unavowed anxiety, the story hit a sour note.
Was he in a state of unavowed love?
The homosexuals Treacher preferred were dry, acerbic and, of course, unavowed; A. E. Housman the type that he approved of, minus the poetry, of course, and (though this was less important) minus the atheism".
There are implications of incest, as well as of an unavowed lesbian attachment played out through the sons.
To write a history of something so ill-defined, so diverse and ephemeral, so frequently silent, invisible and unavowed, requires a truly special sort of historian, like Stengel.
Using four-star jokes to illustrate his points, he argues that all humor hides an impulse of "aggression or apprehension," and that laughter is itself a reflex produced by "repressed sadism, sexual tumescence, unavowed fear, even boredom".
