Break cover, initially appearing in sloop-rigged vessel (7)
I believe the answer is:
holiday
'break' is the definition.
(I've seen this before)
'cover initially appearing in sloop-rigged vessel' is the wordplay.
I cannot quite see how this works, but
'cover' could be 'lid' (lid is a kind of cover) and 'lid' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for holiday that I've seen before include "given a break" , "See 8" , "Break from work" , "Time off work" , "Vacation" .)