Recognise or recognition (used in a negative context only).
Use:
He didn't give him a reck or He didn't reck him.
He didn't recognise him.
Derivation:
Teutonic, Old English 'Reccan' - to pay heed to. (Concise Oxford Dictionary). And note 'Reck' - to take heed of, care for, reward (Scotland, London, Yorkshire). (Wright).