Calms notedly rough seas (5)
I believe the answer is:
eases
'calms' is the definition.
(I've seen this before)
'notedly rough seas' is the wordplay.
I cannot quite see how this works, but
an anagram of 'seas' is 'ases' which is located in the answer.
A single letter 'e' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for eases that I've seen before include "provides relief" , "Softens" , "Relieves, lightens" , "Assuages or slackens" , "Facilitates" .)