Got into bed drunk around one (8)
I believe the answer is:
Here is my best explanation:
'got' is the definition.
(obtaining is a kind of getting)
'into bed drunk around one' is the subsidiary indication.
'drunk' is an anagram indicator.
'around' is an insertion indicator.
'one' becomes 'a'.
'intobed' anagrammed gives 'obtined'.
'obtined' going around 'a' is 'obtained'.
(Other definitions for obtained that I've seen before include "Acquired", "Got, procured", "Procured", "Got something", "Came into possession of" and "Into a bed (anag.)".)