expression, noun
absolute beginner; complete amateur
Emphatic phrase stressing total lack of experience or skill. Often used self-deprecatingly or to describe someone clearly out of their depth.
ずぶの素人なのに、いきなりプロの大会に出るなんて無茶だ。
It's reckless to suddenly enter a professional tournament when you're a complete amateur.
彼は料理に関してはずぶの素人で、包丁すらまともに握れない。
He's an absolute beginner when it comes to cooking; he can't even hold a kitchen knife properly.