Define Up To Eleven Meaning

An adjective describing something that exceeds its perceived upper bounds.

Taking something one past the limit.
From "This is Spinal Tap" refering to guitar amps only going up to 10.

I term used in the movie "This is Spinal tap" It is another way of say "I'll give it 110%"

Thus meaning you'll give whatever you are doing extra effort.

normally you'd say let's crank this shit up to eleven because its soemthing really awesome and cool and you wanna take it to the next level