(British)

Under the influence of drugs, especially pep pills or amphetamines. This word was popular in the early 1960s among mods, who used it to refer to the state of intoxication caused by 'pep pills' or amphetamines, such as purple hearts, blues, black bombers, etc. The origin is probably in the idea that one's block, or head, is completely taken over and partly incapacitated by the drug. This is rein- forced by the fact that a side-effect of amphetamines is to make the user tongue-tied, so that communication is literally blocked.

'"Does that mean you're blocked out of your mind on stage?"

"It means we're blocked out of our minds all the time".'

(Pete Townshend of The Who, interviewed on the television programme A Whole Scene Going, 1966).