Etymology

Verb

1. To react (or cause to react) with extreme anger or fear to something to the extent that one loses one's composure or behaves irrationally; originally, to suffer an unexpected and severe bad reaction from the recreational use of a psychotropic - usually hallucinogenic - drug,
   • 1991, Thelma and Louise (movie)

     Jimmy'll come in off the road, you won't be there, he'll freak out and call you a hundred thousand times...