Notable English pit not without oxygen (7)
I believe the answer is:
eminent
'notable' is the definition.
(I've seen this before)
'english pit not without oxygen' is the wordplay.
'english' becomes 'e' (abbreviation).
'pit' becomes 'mine' (mining pit).
'without' indicates named letters should be taken away.
'oxygen' becomes 'O' (atomic symbol for oxygen).
'not' with 'o' taken out is 'nt'.
'e'+'mine'+'nt'='EMINENT'
(Other definitions for eminent that I've seen before include "Outstanding or distinguished (7)" , "Respected; distinguished" , "Met nine who were distinguished" , "Illustrious like cardinal?" , "Respected; outstanding" .)