Bleah defies definition. It can be used in many forms, such as...
1. Tiredness/ disgust.
"Bleah, I'm so tired."
or
"Bleah."
2. Exclamation of joy.
"Yay, school is over, bleah!"
or
"Bleah!"
3. Agreement.
"Bleah, thats right."
or
"Bleah!"
4. Disagreement.
"Bleah... I dunno."
or
"Bleah..."
A term of whitebread affection, usually employed by dumb Texan rednecks.
SHiiiiiiiiiiiiiiiittt, Nuk!