Unassuming ways associated with tour's leader (6)
I believe the answer is:
modest
'unassuming' is the definition.
(similar in meaning)
'ways associated with tour's leader' is the wordplay.
'ways' becomes 'modes' ('mode' can be a synonym of 'way').
'associated with' means one lot of letters go next to another.
'tour's leader' becomes 't' (I can't explain this - if you can you should believe this answer much more).
'modes'+'t'='MODEST'
Can you help me to learn more?
(Other definitions for modest that I've seen before include "Not vain, rather shy" , "Humble, unpretentious" , "Native of Vienna" , "Simple, humble" , "Prudent" .)