not attractive and awkward or socially embarrassing

He's nice, but kind of nerdy. 他人挺好的，就是有点书呆子气。

These glasses make me look/feel nerdy. 这副眼镜让我显得/感觉很有点书呆子气。

extremely interested in one subject, especially computers, and knowing a lot of facts about it

There is a perception of IT people being nerdy geeks working in isolated backroom office jobs. 人们认为IT人员是在隔绝无窗的密室中工作的电脑高手。

The smart, nerdy kids weren't invited to eat lunch with the cool kids. 那些功课好、书呆子气的孩子没有被邀请和酷孩子们一起吃午饭。