look up any word, like timebomb:
 
4.
Someone with a lack of possibility. Otherwise known as a moron.

Refer to examples such as jeremy's face or shahpur's arguments.

Person1: Your face is invalid.
Jeremy: What?
Person1: Point proven

Shahpur: I am epic
Person1: o really?
Shahpur: I walked in uber cold weather without gloves or scarf for 30 mins
Person1: I walked in uber hot weather without gloves or scarf

Person1 = WIN
Shahpur = INVALID
by s3xy_c4t December 07, 2008
 
1.
1) One who is no longer able to use his/her mind.

2) Not effectual; void.
1) The disease turned Marty into an invalid before killing him; we miss him dearly.

2) The ticket is invalid west of the Mississippi, though, so choose carefully.
by Diggity Monkeez April 08, 2005
 
2.
Inconsistent with some web programmer's arbitrary and frequently incorrect notion of how the world should be.
A: Why does that web site say that your university is in England when it is really in Sweden?

B: Because when I enter the correct address, the web site rejects the postal code as 'invalid'.
by P J Wonko March 14, 2013
 
3.
A extremely stupid person who is useless in any way, shape or form. They often have problems pronouncing simple words like saying stop as shtop, and spelling words incorrectly, like problem as promblem and Ottawa as Ottowa. Could be a person who is physically invalid or mentally invalid.
An example of Mentally:
1: Hey, what's your name?
2: Allen.
1: Invalid.

An example of Physically:
1: Hey, what's your name?
2: Allen.
1: Invalid.
by Laundry Steve July 10, 2008
 
5.
1. When someone says something completely irrevelant to the convo.

2. When someone says something completely stupid in a convo

1. A "you goin to the concert?
B "Yh, gonna get sum kfc"
A "INVALID!?!? wtf

2. A "yh dat was of da hook yo!"
B."it was very elegant"
A. Invalid
by badda trims April 20, 2006