The phrase "as mendacious" is correct and usable in written English.
It can be used to describe something or someone as being deceitful or dishonest, often in a comparative context.
Example: "His claims about the project were as mendacious as the rumors circulating about his past."
Alternatives: "as deceitful" or "as dishonest".
The right-wing newspaper Gazeta Polska characterized the film as "mendacious and harmful for Poles".
Brett Easton Ellis' screenplay offers us three main characters all as mendacious and narcissistic as one another.
In retrospect, the industry response to environmental regulation in the 1970s can best be described as mendacious, homicidal, greedy whingeing.
Inners denounce the poster as mendacious, while becoming increasingly worried that the outer strategy could be working.
Spacey hams it up splendidly as mendacious whip Frank Underwood, plotting to unseat the President with the help of a wet-behind-the-ears political reporter (Kate Mara).
He launched a robust defence of his decision to describe Grant's evidence as "mendacious smears", declaring that the actor's claim that a story about him may have been sourced from phone hacking was damaging to his newspaper.
Germany's pundits spluttered with rage: the Greeks were mendacious as well as impertinent.This week marked a nadir in relations between Greece and its largest creditor.
The new members of the cast appear to be every bit as incompetent and mendacious as the ones we already know.
Undertaken from 1979 to 1983, the much-litigated and not always conclusively documented story of its construction has much to divert both those who would see Trump as a visionary deal-maker or as a mendacious double-dealer.
As for the ending, it is pure fantasy, and could be condemned as essentially mendacious.
America, in turn, sees Iran as "devious, mendacious, fanatical".
