an unmanly man; a mollycoddle (a pampered or effeminate boy or man)
About the word:
Milksop literally means "bread soaked in milk." Chaucer was among the earliest to use milksop to describe an unmanly man (presumably one whose fiber had softened). By the way, the modern cousin of milksop, milquetoast, comes from Caspar Milquetoast, a timid cartoon character from the 1920s.