What is the full name for beau?

Answer 1

beau or bel (masc), belle (fem) means beautiful in English. The plural forms are "beaux" (masc) and "belles" (fem). the word "beau / beaux" was also used by authors from the 19th century in some books. It was used to describe an adult, often superficial, masculine character, interested in women. These characters were often somewhat well-off and proud of their physical appearance. In that sense it no more used in modern French.

Answer 2

A beau is a dated term for a man with a reputation for fine dress and etiquette, or a male boyfriend or lover.