Ecstasy dropped into wine as principle? (5)
I believe the answer is:
tenet
'principle?' is the definition.
(a tenet is a principle or value)
'ecstasy dropped into wine' is the wordplay.
'ecstasy' becomes 'E' (informal term for the drug).
'dropped into' indicates putting letters inside.
'wine' becomes 'tent' (I've seen this before).
'e' placed into 'tent' is 'TENET'.
'as' is the link.
(Other definitions for tenet that I've seen before include "Conviction" , "Item of belief" , "Key principle" , "Article of faith; doctrine" , "Opinion held to be true" .)