noun
idiot; shitbrain
Strongly derogatory insult; roughly equivalent to calling someone a stupid fool or shithead. Used in very informal, angry, or contemptuous speech.
あんなくそたわけの言うことなんか聞くな。
Don't listen to what that idiot says.
お前は本当にくそたわけだな。
You really are a shitbrain.
Compound of くそ (kuso, 'shit') and たわけ (tawake, 'fool, nonsense'). The exact derivation of たわけ is uncertain, but it is a native Japanese word for foolishness.