Gripping, powerless to hold record (13)
I believe the answer is:
unputdownable
'gripping' is the definition.
(I've seen this before)
'powerless to hold record' is the wordplay.
'powerless' becomes 'unable' (similar in meaning).
'to hold' means one lot of letters goes inside another.
'record' becomes 'putdown' (synonyms).
'unable' placed around 'putdown' is 'UNPUTDOWNABLE'.
(Other definitions for unputdownable that I've seen before include "(Of a book) totally engrossing" , "Riveting" , "describing a wonderful book?" , "Like gripping book" .)