A medic seen regularly at a queue for hormone (10)
I believe the answer is:
adrenaline
'hormone' is the definition.
(adrenaline is a kind of hormone)
'a medic seen regularly at a queue' is the wordplay.
'medic' becomes 'dr' (abbreviation for doctor).
'seen regularly' becomes 'ena' (I can't explain this - if you can you should give a lot more credence to this answer).
'at' is a charade indicator (letters next to each other).
'a queue' becomes 'line' (a line of people).
'a'+'dr'+'ena'+'line'='ADRENALINE'
'for' is the link.
Can you help me to learn more?
(Other definitions for adrenaline that I've seen before include "Stimulating hormone" , "Hormone replacement" , "It stimulates" .)