Barrier hotel ruled out (6)
I believe the answer is:
hurdle
'barrier' is the definition.
(I know that hurdle is a type of barrier)
'hotel ruled out' is the wordplay.
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
'out' is an anagram indicator (out can mean wrong or inaccurate).
'ruled' with letters rearranged gives 'urdle'.
'h'+'urdle'='HURDLE'
(Other definitions for hurdle that I've seen before include "Barrier (to be jumped)" , "Obstacle to jump" , "Obstacle; woven fence" , "Light movable barrier in certain races" , "Obstacle to be jumped over in race" .)