一知半解

  1. (idiom) to have a superficial knowledge of a subject; to know a smattering of sth

“superficial knowledge; a smattering (hearsay) of knowledge”

知道得不全面,理解得也不透彻。

Origin 宋·严羽《沧浪诗话·诗辨》:“有透彻之悟,有但得一知半解之悟。”

Example 我也只得~,不懂什么。(清·颐琐《黄绣球》第八回)