Chinless Wonder is a slur used to describe British in a derogatory way. Reference to inbreeding and a weak gene pool resulting in poor bone structure.
The word Chinless Wonder is a racial slur that has been used historically to degrade and dehumanize british. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to british. If you are unsure about whether or not it is appropriate to use the word Chinless Wonder, it is best to err on the side of caution and avoid using it in any situation.