Those doing a bit of dealing lose head with those working in the house (6)
I believe the answer is:
ushers
'those doing a bit of dealing lose head' is the definition.
I can't tell whether this defines the answer.
'those working in the house' is the wordplay.
'those' becomes 'users' (I can't justify this - if you can you should believe this answer much more).
'working in' means one lot of letters goes inside another.
'the house' becomes 'h'.
'users' placed around 'h' is 'USHERS'.
'with' is the link.
Can you help me to learn more?
(Other definitions for ushers that I've seen before include "Court officials" , "Do they lead" , "Officials stationed at the entrances of courtrooms" , "They escort people to seats" , "They show people to their seats in theatres" .)