Union member seen in Almeida Hotel (5)
I believe the answer is:
idaho
'union member' is the definition.
(the USA is a union of states)
'in almeida hotel' is the wordplay.
'in' says the answer is hidden in the clue.
'IDAHO' is hidden within 'almeida hotel'.
'seen' acts as a link.
(Other definitions for idaho that I've seen before include "agricultural land" , "found in America" , "State of north-west USA" , "US state, capital Boise" , "Rocky Mountain state" .)