Fasten up sections that have turned up (5)
I believe the answer is:
strap
'fasten' is the definition.
(I know that strap is a kind of fasten)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for strap that I've seen before include "Restraining fastener" , "Leather thong" , "Strong band for binding luggage etc" , "Narrow strip of leather" , "punishment in school" .)