I clam up in strange town? (9)
I believe the answer is:
municipal
'town?' is the definition.
(thesaurus)
'i clam up in strange' is the wordplay.
'strange' is an anagram indicator.
'i'+'clam'+'up'+'in'='iclamupin'
'iclamupin' is an anagram of 'MUNICIPAL'.
(Other definitions for municipal that I've seen before include "Of local council" , "Relating to a town/district with local government" , "belonging to the city" , "Civic" , "Borough" .)