Very positive man serving from the East in hotels (4)
I believe the answer is:
high
'very positive' is the definition.
(high can mean optimistic or happy)
'man serving from the east in hotels' is the wordplay.
'man serving' becomes 'GI' (GI can mean an American soldier).
'from the east' says the letters should be written backwards (on a map from right to left).
'in' is an insertion indicator.
'hotels' becomes 'HH' (two H's - hotel is H in the NATO phonetic alphabet).
'gi' in reverse letter order is 'ig'.
'ig' inserted into 'hh' is 'HIGH'.
(Other definitions for high that I've seen before include "Eminent; lofty" , "American school" , "(Of meat) slightly decomposed" , "Large, complex (and shady?) money transactions" , "State of euphoria" .)