From Longman Dictionary of Contemporary Englishshit yourselfshit yourself spoken not politeBritish English, shit (in) your pants American EnglishFRIGHTENED to feel very worried or frightened → shit
Examples from the Corpus
shit yourself• To shit oneself is to admit existence.• He shits himself each day that they will send him there.• Fact is, comin' here from the fence I fuckin' near shit myself each time you stopped. 