Tramps removing hospital instruments (5)
I believe the answer is:
oboes
'instruments' is the definition.
(oboe is a kind of instrument)
'tramps removing hospital' is the wordplay.
'tramps' becomes 'hoboes' ('hobo' can be a synonym of 'tramp').
'removing' suggests deleting specific letters.
'hospital' becomes 'h'.
'hoboes' with 'h' taken out is 'OBOES'.
(Other definitions for oboes that I've seen before include "Woodwind instruments" , "They're instrumental" , "Parts of orchestra" , "members of orchestra" , "Wind instruments" .)