Become bitter (4)
I believe the answer is:
sour
(Other definitions for sour that I've seen before include "Bitter, tart" , "Acid tasting" , "Acrid or sullen" , "Vinegary" , "Curdled" .)
I believe the answer is:
sour
(Other definitions for sour that I've seen before include "Bitter, tart" , "Acid tasting" , "Acrid or sullen" , "Vinegary" , "Curdled" .)