Apart, and sure to be reassembled (7)
I believe the answer is:
asunder
'apart' is the definition.
(I've seen this before)
'and sure to be reassembled' is the wordplay.
'to be reassembled' indicates anagramming the letters.
'and'+'sure'='andsure'
'andsure' with letters rearranged gives 'ASUNDER'.
(Other definitions for asunder that I've seen before include "being in two" , "(Torn) into parts" , "(Break) apart" , "bits?" , "Apart - in pieces" .)