Terribly hardy, Edward, when given water (8)
I believe the answer is:
hydrated
'given water' is the definition.
The definition and answer can be both related to change as well as being past participle verbs.
Perhaps they are linked in a way I don't understand?
'terribly hardy edward' is the wordplay.
'terribly' indicates anagramming the letters.
'edward' becomes 'ted'.
'hardy' anagrammed gives 'hydra'.
'hydra'+'ted'='HYDRATED'
'when' is the link.
Can you help me to learn more?
(Other definitions for hydrated that I've seen before include "so after a drink" , "Watery" .)