Mad
/ˈmæːd/
verb
To be or become mad.
To madden, to anger, to frustrate.
adjective
Insane; crazy, mentally deranged.
“He's got this mad idea that he's irresistible to women.”
(chiefly US; informal in UK) Angry, annoyed.
“Are you mad at me?”
Bizarre; incredible.
“It's mad that I got that job back a day after being fired.”
adverb
Intensifier; to a large degree; extremely; exceedingly; very; unbelievably.
“He seems mad keen on her.”