Drop off tin with leak (6)
I believe the answer is:
snooze
'drop off' is the definition.
(I've seen this before)
'tin with leak' is the wordplay.
'tin' becomes 'sn' (Sn is the chemical symbol for tin).
'with' says to put letters next to each other.
'leak' becomes 'ooze' (I've seen this before).
'sn'+'ooze'='SNOOZE'
(Other definitions for snooze that I've seen before include "A brief nap" , "Doze, nap" , "Take a brief light sleep" , "A short informal sleep" , "Quick nap" .)