Infant's woe (5)
I believe the answer is:
colic
'infant's woe' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for colic that I've seen before include "Abdominal pain spasms" , "Spasmodic abdominal pain" , "unpleasant gut feeling" , "Acute abdominal pain" , "Abdominal pain suffered by babies and horses" .)