Jotted down notes, being calm (8)
I believe the answer is:
composed
'calm' is the definition.
(similar in meaning)
'jotted down notes being' is the wordplay.
I cannot quite see how this works, but
'down' could be 'd' and 'd' is located in the answer.
'being' could be 'mp' (MP is an example) and 'mp' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for composed that I've seen before include "Still - contrived" , "What poet did" , "Field did" , "Unruffled" , "Made a score" .)