Bring up doctor to border (6)

I believe the answer is:
dredge
'bring up' is the definition.
Although both the answer and definition are verbs in their base form, I cannot see how one could define the other.
'doctor to border' is the wordplay.
'doctor' becomes 'dr' (abbreviation).
'to border' becomes 'edge' (synonyms).
'dr'+'edge'='DREDGE'
Can you help me to learn more?
(Other definitions for dredge that I've seen before include "Deepen a waterway" , "Remove mud from a riverbed" , "dragnet" , "Sprinkle, deepen" , "Clear (riverbed)" .)
