swagのようなどんな単語でも探してください。
 
1.
Person who fails to achieve his or her potential. Used often when refering to students.
My kid is an underachiever. He's not an idiot though.
jakub777によって 2008年10月24日(金)
 
2.
A female whose stomach petrudes farther outward from her body than her breasts.
Look at that fat chick with tiny boobs. What an under achiever!
will_minnesotaによって 2006年07月09日(日)
 
3.
The opposite of:

overachiever
44 up, 15 down
Someone who is sooo much better than you that it pisses you off.

I hate that fucking overachiever!

by Blah Aug 8, 2003 email it
Yeah so what if all I did was copy and paste the definition of overachiever. I'm a true underachiever.
rappatheredによって 2008年03月25日(火)
 
4.
A person who does not perform to one's expectations.

A person who disappoints.
Dr. Manmohan Singh Indian Prime Minister
as described very well by Time Magazine. He was depicted on the front page as underachiever.
Shobitによって 2012年09月29日(土)