European secretary’s first son at Westminster? (5)
I believe the answer is:
swiss
'european' is the definition.
(Switzerland is in Europe)
'secretary's first son at westminster?' is the wordplay.
'secretary's first' becomes 's' (1st letter of 'secretary').
'son' becomes 's' (genealogical abbreviation for son).
'at' means one lot of letters go next to another (I've seen this in other clues).
'westminster?' becomes 'swi' (resembles SW1, London postcode).
's'+'s'='ss'
'ss' put after 'swi' is 'SWISS'.
(Other definitions for swiss that I've seen before include "Like Gruyere, Emmental" , "One from Basle" , "Helvetic" , "William Tell's nationality" , "Nationality of Carl Jung" .)