Somehow, I want a rook like a dove (7)
I believe the answer is:
antiwar
'like a dove' is the definition.
(dove can mean an advocate of peace)
'somehow i want a rook' is the wordplay.
'somehow' is an anagram indicator.
'rook' becomes 'r' (abbreviation in chess).
'i'+'want'='iwant'
'iwant' anagrammed gives 'antiw'.
'antiw'+'a'+'r'='ANTIWAR'
(Other definitions for antiwar that I've seen before include "Promoting peace" , "of the Pacific class" , "pacifist" , "opposed to aggression" , "like a dove" .)