Run the water for the plant (9)
I believe the answer is:
speedwell
'plant' is the definition.
(speedwell is a kind of plant)
'run the water' is the wordplay.
I cannot really understand how this works, but
'run' could be 'well' (I've seen this before) and 'well' is found within the answer.
'water' could be 'pee' (synonyms) and 'pee' is located in the answer.
This explanation may well be incorrect...
'for the' acts as a link.
Can you help me to learn more?
(Other definitions for speedwell that I've seen before include "Small blue flower of the genus veronica" , "Small creeping herbaceous plant with blue or pink flowers" , "bloomer?" , "Small plant, veronica" , "Flowering plant" .)