Garden creeper (5)
I believe the answer is:
snail
'garden creeper' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for snail that I've seen before include "Sluggish person - kind of mail" , "Edible terrestrial mollusc" , "Common garden mollusc" , "Slow-moving garden pest" , "Proverbially slow-moving mollusc" .)