Learned to control oxygen escaping soon after taking lid off (9)
I believe the answer is:
scholarly
'learned' is the definition.
('scholarly' can be similar in meaning to 'learned')
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for scholarly that I've seen before include "Erudite" , "in academic style?" , "Learned, academic" , "Involving serious academic study" .)