Believed ruffian about hotel bar (7)
I believe the answer is:
thought
'believed' is the definition.
('think' can be a synonym of 'believe')
'ruffian about hotel bar' is the wordplay.
'ruffian' becomes 'tough' (I can't explain this - if you can you should believe this answer much more).
'about' is an insertion indicator.
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
'bar' becomes 't' (T-bar is a part of a ski lift).
'tough' going around 'h' is 'though'.
'though'+'t'='THOUGHT'
Can you help me to learn more?
(Other definitions for thought that I've seen before include "Meditation" , "just a trifle" , "Orwell's sort of police" , "Cogitated" , "Notion" .)