Analyse water flowing through Hampshire (4)
I believe the answer is:
test
I believe this clue is a double definition.
'analyse' is the first definition.
(I've seen this before)
'water flowing through hampshire' is the second definition.
(River Test)
(Other definitions for test that I've seen before include "water flowing through Hampshire" , "Trial; cricket match" , "Cricket match; exam" , "Ward off" , "Assay" .)