Laurel spreads in eastern edge of allotment fast (7)
I believe the answer is:
instant
'fast' is the definition.
(similar in meaning)
'laurel spreads in eastern edge of allotment' is the wordplay.
I cannot really understand how this works, but
'laurel' could be 'stan' (comedian Stan Laurel is an example) and 'stan' is located in the answer.
'in' is within the answer.
A single letter 't' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for instant that I've seen before include "A second - coffee, maybe" , "The blink of an eye" , "Split second" , "No need to cook" , "Trice" .)