Save queen coming out of passage (6)
I believe the answer is:
except
'save' is the definition.
(I've seen this before)
'queen coming out of passage' is the wordplay.
'queen' becomes 'r' (r is abbreviation regina. e.g. in ER ).
'coming out of' indicates named letters should be taken away.
'passage' becomes 'excerpt' (excerpt is a kind of passage).
'excerpt' with 'r' taken away is 'EXCEPT'.
(Other definitions for except that I've seen before include "Leaving out" , "Save for" , "Rule out - unless" , "Not including - bar" , "Not including or leave out" .)