When the weeds rank of dank makes you that way. The name comes from the above the influence commercial called "flat".
Other symptoms of being flat include being anti-social
2. The name given to someone who is not cool and is dull and boring
3. The name given to a woman with no or hardly any breasts.
4. Something which is level, does not decrease or increase.
5. The name given to something filled with air which is now de-flated.
2. Stop being so flat, come to the party!
3. I realised last nite that my girlfriend was flat and she had been putting tissue in her bra, damn!
4. This years profit margin was flat.
5. Shit! How am i going to get to the prom now, the god damned tyres are flat.