Manage to keep cool about some intractable letters (7)
I believe the answer is:
control
This could be a double definition.
'manage' is the first definition.
(I know that manage is a more specific form of control)
'keep cool about some intractable letters' is the second definition.
'control' can be an answer for 'keep' (thesaurus). I'm not sure about the 'cool about some intractable letters' bit.
'to' is the link.
Can you help me to learn more?
(Other definitions for control that I've seen before include "Regulating device" , "Regulation" , "Handle, operate" , "Regulate with self-possession?" , "Regulate; spymaster" .)