Not so many on express without nationality (9)
I believe the answer is:
stateless
'without nationality' is the definition.
('nationality' can be 'state' (thesaurus) so maybe 'without nationality' can be ''stateless')
'not so many on express' is the wordplay.
'not so many' becomes 'less' (I've seen this in another clue).
'on' means one lot of letters go next to another.
'express' becomes 'state' (stating is a kind of expressing).
'less' put after 'state' is 'STATELESS'.
(Other definitions for stateless that I've seen before include "Unrecognised by any country" , "Condition of a person unable to obtain a passport" , "those without nationhood" , "With no nationality" , "Not a citizen of any country" .)