Hospital assistant in love with doctor returned to emergency room lobby disheartened (7)
I believe the answer is:
orderly
'hospital assistant in love with doctor' is the definition.
I can't judge whether this definition defines the answer.
'returned to emergency room lobby disheartened' is the wordplay.
'returned to' becomes 'ord' (I can't justify this - if you can you should believe this answer much more).
'emergency room' becomes 'ER' (abbreviation popularized by US TV series).
'disheartened' suggests removing the centre (the middle or heart is removed).
'lobby' with its middle removed is 'ly'.
'ord'+'er'+'ly'='ORDERLY'
Can you help me to learn more?
(Other definitions for orderly that I've seen before include "Tidy officer's attendant" , "Well-regulated" , "An officer's servant, tidy chap" , "Hospital attendant; well behaved" , "Neat, tidy; soldier" .)