A man who acts as a child and does not accept the responsibilities of adulthood.

plural of Peter Pan

(idiomatic) The supposed psychological phenomenon of immaturity among some men, who, like the fictional character, remain childish and fail to assume appropriate adult social roles and responsibilities.

A flat collar with rounded ends, cut to fit around the curve of the neckline, usually white or pale-coloured.

plural of Peter Pan collar

Generation Y