Reptile to go off, briefly let out (6)
I believe the answer is:
turtle
'reptile' is the definition.
(turtle is a kind of reptile)
'go off briefly let out' is the wordplay.
I cannot really understand how this works, but
an anagram of 'let' is 'tle' which is located in the answer.
This may be the basis of clue (or it may be nonsense).
'to' is the link.
Can you help me to learn more?
(Other definitions for turtle that I've seen before include "Aquatic or terrestial reptile" , "See 7" , "Sea swimmer" , "Marine reptile of the order Chelonia" , "Shelled marine creature" .)