Plain damage I repair (7)
'plain' is the definition.
'damage i repair' is the wordplay.
'damage' indicates an anagram (I've seen this in other clues).
'irepair' anagrammed gives 'PRAIRIE'.
(Other definitions for prairie that I've seen before include "this oyster produces an egg", "Tract of (US) grassland", "Broad rolling tract of land in the US", "Extensive US grassland", "Large tract of grassland in N America".)