Became less ragged after trim (5)
I believe the answer is:
eased
'became less' is the definition.
(to ease or ease off can mean to decrease)
'ragged after trim' is the wordplay.
'ragged' becomes 'teased' (rag can mean to tease or mock).
'after trim' means to remove the first letter (the first letter is trimmed off).
'teased' with its initial letter taken away is 'EASED'.
(Other definitions for eased that I've seen before include "Made less stressful or difficult" , "relented" , "Made less difficult or trying" , "Relieved, mitigated" , "Became less painful" .)