Expert in garden centre didn't linger (5)
I believe the answer is:
raced
'didn't linger' is the definition.
I can't judge whether this defines the answer.
'expert in garden centre' is the wordplay.
'expert' becomes 'ace' (ace can informally mean very good).
'in' is an insertion indicator.
'centre' says to take the centre.
The middle of 'garden' is 'rd'.
'ace' going inside 'rd' is 'RACED'.
Can you help me to learn more?
(Other definitions for raced that I've seen before include "Ran competitively" , "Competed" , "Dashed" , "Rushed" , "Ran fast" .)