Netherlands city (7)
(Other definitions for rotterdam that I've seen before include "European city" , "Netherlands port" , "Major world seaport at the mouth of the Meuse" , "Major North Sea port - tarred tom (anag)" , "foreign city" .)
'netherlands city' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for utrecht that I've seen before include "Netherlands province" , "Dutch city where treaty was signed in 1713" , "City of historic treaty, 1713" , "Netherlands city, scene of 1713 Treaty" , "European city" .)