Maybe one's bowled over family doctor with case of indigestion (7)
I believe the answer is:
kingpin
'maybe one's bowled' is the definition.
I can't tell whether this definition defines the answer.
'family doctor with case of indigestion' is the wordplay.
'family' becomes 'kin' (synonyms).
'doctor' becomes 'GP' (general practitioner).
'with' means one lot of letters go next to another.
'case of' suggests removing the centre (like emptying a case).
'indigestion' with its centre taken out is 'in'.
'kin'+'gp'+'in'='KINGPIN'
'over' acts as a link.
Can you help me to learn more?
(Other definitions for kingpin that I've seen before include "Essential person or thing" , "first to be hit by a strike?" , "Crucial person in organisation" , "Main bolt" , "Most important member of organisation" .)