Office panel upset with others training staff (9)
I believe the answer is:
nameplate
'office panel' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'upset with others training staff' is the wordplay.
'upset' is a reversal indicator.
'with others' becomes 'et al' (short for 'et alia', Latin for 'and others').
'training' becomes 'PE' (Physical Education).
'staff' becomes 'man' (as in staffing or manning a particular place).
'etal'+'pe'+'man'='etalpeman'
'etalpeman' in reverse letter order is 'NAMEPLATE'.
Can you help me to learn more?
(Other definitions for nameplate that I've seen before include "sign of ownership" , "for handle at entrance" , "It may be attached to an office door" , "Notice telling who is the occupant" , "Occupant's identification" .)