偏科 piānkē
[tend to go overboard on one or some subjects] 教学或学习中只注重某一门或某几门课程而忽视其他课程
大陆地区用语:(1) 偏重某些科目。(2) 冷僻的科目。
英语 to overemphasize some topic (at the expense of others), overdoing it, to go overboard