Lime and dash of Drambuie in Between The Sheets (6)
I believe the answer is:
linden
'lime' is the definition.
(synonyms)
'dash of drambuie in between the sheets' is the wordplay.
'dash of' says to take the initial letters (a small amount of the word).
'in between' means one lot of letters goes inside another.
'the sheets' becomes 'linen' (I've seen this before).
The initial letter of 'drambuie' is 'd'.
'd' put inside 'linen' is 'LINDEN'.
'and' is the link.
(Other definitions for linden that I've seen before include "Lime tree" , "type of tree" , "Tree with Lea - also called 8" , "One twigged" , "Unter den ------, iconic boulevard in Berlin" .)