A second amount of money? Ecstasy! Take it! (6)
I believe the answer is:
assume
'take it' is the definition.
(thesaurus)
'a second amount of money? ecstasy' is the wordplay.
'a second' becomes 'as' (I've seen this in other clues).
'amount of money?' becomes 'sum' ('sum' can be a synonym of 'amount of money').
'ecstasy' becomes 'e' (informal term for the drug).
'as'+'sum'+'e'='ASSUME'
(Other definitions for assume that I've seen before include "Dark brown fur" , "Be arrogant" , "Adopt falsely" , "Take as true or take for granted" , "Take for granted, suppose" .)