They bore a doctor with ailments (6)
I believe the answer is:
drills
'they bore' is the definition.
(I've seen this before)
'a doctor with ailments' is the wordplay.
'a doctor' becomes 'Dr' (abbreviation).
'with' says to put letters next to each other.
'ailments' becomes 'ills' ('ill' can be a synonym of 'ailment').
'dr'+'ills'='DRILLS'
(Other definitions for drills that I've seen before include "Boring tools" , "monkeys" , "Potato rows" , "Trains, in military fashion" , "Tools with a sharp points for making holes" .)