Worse than dry? I'll supply water (7)
I believe the answer is:
hydrant
'i'll supply water' is the definition.
(a hydrant supplies water)
'worse than dry?' is the wordplay.
'worse' indicates anagramming the letters (a worse or damaged version of the letters).
'than'+'dry'='thandry'
'thandry' with letters rearranged gives 'HYDRANT'.
(Other definitions for hydrant that I've seen before include "Connection for attaching hose to water-main" , "Water source" , "Outlet from water main for connecting to hoses" , "Fire hose supplier" , "Main connection" .)