Being not good at something; a weakness or area where one lacks skill or confidence.
数学は私の不得意な科目だ。
Math is a subject I'm not good at.
彼は料理が不得意なので外食が多い。
He's not good at cooking, so he eats out a lot.
プレゼンは不得意だが、練習すれば上手くなると思う。
I'm not good at presentations, but I think practice will improve me.