Waylay a doctor in front of American hospital (6)
I believe the answer is:
ambush
'waylay' is the definition.
('ambush' can be a synonym of 'waylay')
'a doctor in front of american hospital' is the wordplay.
'doctor' becomes 'mb' (Bachelor of Medicine, Medicinae Baccalaureus**).
'in front of' is a charade indicator (letters next to each other).
'american' becomes 'us'.
'hospital' becomes 'h'.
'a'+'mb'+'us'+'h'='AMBUSH'
(Other definitions for ambush that I've seen before include "Surprise attack" , "Await and intercept unexpectedly" , "Waylay" , "Lie in wait; trap" , "Scene of lying in wait" .)