Means of administering food or medicine intravenously (4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
drip
(Other definitions for drip that I've seen before include "Fall from a leaking tap - weakling" , "Fall in small amounts" , "Weed - seep" , "Wimp" , "Intravenous administration of solution" .)