the moment at which someone (or something) who has been consistently dependable suddenly collapses or disintegrates, due to age or any other factor
this phrase was popularized (and perhaps created) by Bill Simmons of ESPN as a candidate to replace jump the shark, it references the decline of the NBA's Gary Payton which became shockingly apparent in the 2004 NBA playoffs
Before marrying my girlfriend, my intuitions warned me that her libido eventually will go GP on us.
A sunburn or suntan focused on the left arm. It is caused by the left side of the body being the only half that gets exposed to sunlight while driving. Presumably, it would be located on the right side of the body in countries where they drive on the left side of the road.
British slang for a scientist or technical expert, esp . when the speaker is not certain of the expert’s specific field of study. Not necessarily derogatory, but typically used by persons without a technical background. In the US, the equivalent would be “egghead”, “squint”, or “geek.”
Origin of the word is unknown. Started sometime in World War 2. Given the typical evolution of British slang, could easily have started because what these experts did was confusing or “baffling” to the common person.