The Bishop's Licence is bestowed upon a gentleman when his wife is down the shops or otherwise engaged away from the house, and confers on him the right, nay, the duty to wank himself blind.

A phrase to describe someone who is cognitively degenerating. Synonym of "going off the deep end". Can have varying degrees of severity.

Reference to the song "Hey You" by Pink Floyd. The line "and the worms ate into his brain" makes no sense in an otherwise linear and literal narration throughout the lyrics.