Had tree replaced safe from lightning (7)
I believe the answer is:
earthed
'safe from lightning' is the definition.
The answer and definition are not the same part of speech. However, adjectives and past participle verbs occasionally define each other.
'had tree replaced' is the wordplay.
'replaced' indicates an anagram.
'had'+'tree'='hadtree'
'hadtree' is an anagram of 'EARTHED'.
Can you help me to learn more?
(Other definitions for earthed that I've seen before include "protected from shock" , "attached to the ground" , "grounded" .)