Mischievously stole time, finding excuse for a kiss? (9)
I believe the answer is:
mistletoe
'excuse for a kiss?' is the definition.
(people kiss under mistletoe at Christmas)
'mischievously stole time' is the wordplay.
'mischievously' indicates anagramming the letters (I've seen this in other clues).
'stole'+'time'='stoletime'
'stoletime' with letters rearranged gives 'MISTLETOE'.
'finding' acts as a link.
(Other definitions for mistletoe that I've seen before include "Yuletide hanging?" , ""Kissing" sprig" , "Something to stand under when kissing?" , "Tree parasite" , "People kiss under this plant" .)