Detest dogs initially peeing next to hospital compound (9)
I believe the answer is:
phosphate
'compound' is the definition.
(phosphate is a kind of compound)
'detest dogs initially peeing next to hospital' is the wordplay.
'detest' becomes 'hate' (synonyms).
'dogs' says to put letters next to each other (dogs can mean follows or chases).
'initially' suggests taking the first letters.
'next' is a charade indicator (letters next to each other) (I've seen this in other clues).
'to hospital' becomes 'hosp' (I can't explain this - if you can you should believe this answer much more).
The initial letter of 'peeing' is 'p'.
'p'+'hosp'='phosp'
'hate' put after 'phosp' is 'PHOSPHATE'.
Can you help me to learn more?
(Other definitions for phosphate that I've seen before include "Salt used in fertilizers" , "Hope paths lead to artificial fertiliser" , "Acid salt used, eg, as a fertiliser" .)