Oblivious Iran not, strangely, accepting gravity (8)
I believe the answer is:
ignorant
'oblivious' is the definition.
(thesaurus)
'iran not strangely accepting gravity' is the wordplay.
'strangely' is an anagram indicator.
'accepting' is an insertion indicator.
'gravity' becomes 'g'.
'iran'+'not'='irannot'
'irannot' with letters rearranged gives 'inorant'.
'inorant' placed around 'g' is 'IGNORANT'.
(Other definitions for ignorant that I've seen before include "Empty-headed" , "Lacking knowledge or skill" , "Uncouth or uninformed" , "No rating (anag) - in the dark" , "Lacking in education" .)