Salt from messy shop public house consumed (9)
I believe the answer is:
phosphate
'salt' is the definition.
(phosphate is a kind of salt)
'messy shop public house consumed' is the wordplay.
'messy' is an anagram indicator.
'public house' becomes 'ph'.
'consumed' becomes 'ate' (eating is a kind of consuming).
'shop' with letters rearranged gives 'phos'.
'phos'+'ph'+'ate'='PHOSPHATE'
'from' acts as a link.
(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" .)