Definition of posher:
(adj) :
Stylish; elegant; exclusive; luxurious; expensive.
(adj) :
Associated with the upper classes.
(adj) :
(usually offensive, especially in Ireland, Scotland, Northern England) Snobbish, materialistic, prejudiced, under the illusion that one is better than everyone else.
(v) :
(normally in the phrasal verb posh up) To make posh or posher (more posh).
(n) :
(chiefly dialectal) A sudden and heavy fall or gush of rain or water.
(n) :
(uncountable) Fragments produced by an impact.