Bleak pictures inside arch (7)
I believe the answer is:
spartan
'bleak' is the definition.
Both the answer and definition are adjectives. Maybe you can see an association between them that I don't see?
'pictures inside arch' is the wordplay.
'pictures' becomes 'art'.
'inside' means one lot of letters goes inside another.
'arch' becomes 'span' (I've seen this in another clue).
'art' placed within 'span' is 'SPARTAN'.
Can you help me to learn more?
(Other definitions for spartan that I've seen before include "Of conditions, harsh and lacking comforts" , "Lacking luxury, austere" , "Severe" , "Old citizen" , "Rather austere" .)