It's sweet taking drugs in Hungary on vacation (5)
I believe the answer is:
honey
'it's sweet' is the definition.
(thesaurus)
'taking drugs in hungary on vacation' is the wordplay.
'taking' becomes 'on' (eg one taking drugs is 'on' drugs).
'drugs' becomes 'E' (abbreviation for ecstasy).
'in' means one lot of letters goes inside another.
'on vacation' suggests removing the centre (after the inside letters have vacated the word).
'hungary' with its middle removed is 'hy'.
'on'+'e'='one'
'one' going within 'hy' is 'HONEY'.
(Other definitions for honey that I've seen before include "Substance made by bees" , "Sweet food" , "sweetheart" , "Treasure" , "Hive's product" .)