1 definition by Brian Adelman

Top Definition
an intellectual state in which one is of well below average intelligence.

100% of the time, the mentally fat person is completely unaware of their intellectual condition.

Note: Physically attractive people can most certainly (and often times are) mentally fat.
Man, she was so hot but seriously, that girl is so goddamn mentally fat I could not stand another second in her presence.
by Brian Adelman May 01, 2010

Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from daily@urbandictionary.com. We'll never spam you.

×