A lot of Americans would have the idea that a
Nigel is "effeminate" because of the way the name has been used for British characters in American films.
Nigel and
Reginald both have the image of being "prissy upper class English dolts" to many people in the USA. I know that this is NOT the image of those names in England or Australia, but it's part of their image in North
America.
Also note that "effeminate" is not quite the same thing as "feminine". It refers to behavior, not appearance. A man with a big bumpy nose and
Adam's apple can ACT "effeminate", and that's what's associated with the name in the USA.