Images in solid form (5)
I believe the answer is:
idols
'images' is the definition.
(idol is a kind of image)
'solid form' is the wordplay.
'form' indicates anagramming the letters (another form of the letters).
'solid' is an anagram of 'IDOLS'.
'in' acts as a link.
(Other definitions for idols that I've seen before include "Effigies worshipped as gods" , "Graven images sometimes worshipped" , "Much-admired persons" , "Heroes" , "Solid kind of images" .)