Moving more quickly to secure extremely nice clasp? (8)
I believe the answer is:
Here is my best explanation:
'clasp?' is the definition.
(clasp is a kind of fastener)
'moving more quickly to secure extremely nice' is the wordplay.
'moving more quickly' becomes 'faster' (I've seen this before).
'to secure' means one lot of letters goes inside another.
'extremely' means to remove the middle letters.
'nice' with its middle removed is 'ne'.
'faster' going around 'ne' is 'FASTENER'.