1. High on large amounts of stimulants (amphetamines, cocaine, caffeine, sugar, etc)
2. The point at which, having taken excess amounts of speed, you no longer feel the desire to talk (as you would when more moderately amped)
3. A state of being overstimulated, excited, and/or hyperactive.
He was completely wired after having taken more pills than usual.
On Saturday mornings the children were wired from all the sugar and cartoons.