Dealing with roughly (5)
I believe the answer is:
about
'roughly' is the definition.
(about can mean roughly or approximately)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for about that I've seen before include "'All - - Eve' (film)" , "Engaged in" , "On the topic of" , "in action" , "Concerning or around" .)