Material about eastern Mediterranean region (8)
I believe the answer is:
relevant
'material' is the definition.
(similar in meaning)
'about eastern mediterranean region' is the wordplay.
'about' becomes 're' ('re' means regarding or about).
'eastern mediterranean region' becomes 'levant' (I've seen this in another clue).
're'+'levant'='RELEVANT'
(Other definitions for relevant that I've seen before include "Germane or pertinent" , "Apt" , "To the point" , "Closely connected (to the matter in hand)" , "Significant" .)