This is the 9914th most frequent French word.
foirer
"Foirer" means to mess up or fail.
Here, 'foirer' represents the act of not succeeding or failing at something, colloquial for 'mess up'.
Je ne veux pas foirer cet examen important.
I don't want to mess up this important exam.
In this context, 'foirer' is used informally to indicate an unintentional failure or error in performing an action.
Il a foiré sa présentation à cause du stress.
He screwed up his presentation due to stress.
This sentence uses 'foirer' to imply the risk of poorly executing or failing to achieve a desired outcome due to lack of preparation.