Reveal new bay in ancient city (7)
I believe the answer is:
uncover
'reveal' is the definition.
(synonyms)
'new bay in ancient city' is the wordplay.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'bay' becomes 'cove' (I've seen this in another clue).
'in' is an insertion indicator.
'ancient city' becomes 'ur'.
'n'+'cove'='ncove'
'ncove' going inside 'ur' is 'UNCOVER'.
(Other definitions for uncover that I've seen before include "Make visible" , "bare" , "Expose, unveil" , "make a revelation" , "Reveal - take top off" .)