Holiday garland guaranteed (7)
I believe the answer is:
leisure
'holiday' is the definition.
(thesaurus)
'garland guaranteed' is the wordplay.
'garland' becomes 'lei' ('lei' can be a synonym of 'garland').
'guaranteed' becomes 'sure' (I've seen this in other clues).
'lei'+'sure'='LEISURE'
(Other definitions for leisure that I've seen before include "days off" , "Non-work activity" , "Breathing space" , "Free time as for resting or play" , "idle hours" .)