Ace bed after taking in second course (5)
I believe the answer is:
ascot
'course' is the definition.
(I've seen this before)
'ace bed after taking in second' is the wordplay.
'ace' becomes 'a'.
'bed' becomes 'cot' (cot is a kind of bed).
'after' says to put letters next to each other.
'taking in' indicates putting letters inside.
'second' becomes 's' (common abbreviation).
'a'+'cot'='acot'
'acot' placed around 's' is 'ASCOT'.
(Other definitions for ascot that I've seen before include "Where ladies wear new hats" , "Racing to the strange coast" , "Berkshire racecourse - coast (anag)" , "Racecourse, home to the Gold Cup since 1807" , "Tosca (anag) - racecourse" .)