Pale head gardener from the east, points out what pests tend to do (4)
I believe the answer is:
gnaw
'points out what pests tend to do' is the definition.
I can't tell whether this defines the answer.
'pale head gardener from the east' is the wordplay.
'pale' becomes 'wan' (wan can mean pale or grey).
'head' indicates taking the first letters.
'from the east' says the letters should be written backwards (on a map from right to left).
The first letter of 'gardener' is 'g'.
'wan'+'g'='wang'
'wang' written backwards gives 'GNAW'.
Can you help me to learn more?
(Other definitions for gnaw that I've seen before include "Nibble like a rodent" , "Chew at, work with teeth" , "Chew upon" , "Wear away with the teeth" , "Bite persistently, grind" .)