Guys touring new countries (5)
I believe the answer is:
lands
'countries' is the definition.
('land' can be a synonym of 'country')
'guys touring new' is the wordplay.
'guys' becomes 'lads'.
'touring' means one lot of letters goes inside another (touring can mean going round).
'new' becomes 'n'.
'lads' enclosing 'n' is 'LANDS'.
(Other definitions for lands that I've seen before include "Comes ashore" , "Obtains" , "See 21" , "Alights" .)