When you say something outrageous, but clearly is also true. Usually told to someone who might take offence.
Jim: You have to be in shape to wear a midriff. Looks to me like Jenny needs to hit the gym
Mike: WTF--Jenny is my girl!
Jim: Then you should know.
Stop me when I lie.
Mike: Well…she does look like she has a nick-knack sack.
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.