Following unlimited mounting pain, doctor in charge of feet (6)
I believe the answer is:
iambic
'of feet' is the definition.
(I've seen this before)
'following unlimited mounting pain doctor in charge' is the wordplay.
'following unlimited mounting pain' becomes 'ia' (I can't justify this - if you can you should believe this answer much more).
'doctor' becomes 'mb' (Bachelor of Medicine, Medicinae Baccalaureus).
'in charge' becomes 'ic' (abbreviation for 'in charge').
'ia'+'mb'+'ic'='IAMBIC'
Can you help me to learn more?
(Other definitions for iambic that I've seen before include "Shakespearean verse metre" , "Using short-long metrical feet" , "description of some verse" , "Line of poetry with unstressed-stressed syllables" , "Type of verse" .)