Acquire almanac found in that region (5)
I believe the answer is:
'region' is the definition.
(I've seen this in another clue)
'acquire almanac found in that' is the wordplay.
'in that' indicates the answer is hidden within the clue.
'REALM' is hidden in the letters of 'acquire almanac found'.
(Other definitions for realm that I've seen before include "World" , "Area of interest/activity" , "Monarchy" , "King's domain" , "Lamer (anag.)" .)