Small Christmas gift dizzy girl left in sock (8,6)
I believe the answer is:
stocking filler
'small christmas gift' is the definition.
(I've seen this before)
'dizzy girl left in sock' is the wordplay.
'dizzy' indicates an anagram.
'girl'+'left'+'in'+'sock'='girlleftinsock'
'girlleftinsock' with letters rearranged gives 'STOCKING FILLER'.
(Other definitions for stocking filler that I've seen before include "head of a bank robber, perhaps?" , "Extra Christmas present" , "small Christmas gift" , "Pin, for girl, might be" , "Christmas treat" .)