boo is a term that is derived from the French word beau meaning beautiful. In 18th century England it meant an admirer, usually male. It made it's way into Afro-Caribean language perhaps through the French colonisation of some Caribean islands.oo is a term that is derived from the French word beau meaning beautiful. In 18th century England it meant an admirer, usually male. It made it's way into Afro-Caribean language perhaps through the French colonisation of some Caribean islands.