Sentence:  Warwick observed, as they passed through the respectable quarter, that few people who met the girl greeted her, and that some others whom she passed at gates or doorways gave her no sign of <WSD>recognition</WSD>; from which he inferred that she was possibly a visitor in the town and not well acquainted. 
Meaning of the word marked with <WSD> tags:  the act of recognizing or the condition of being recognized (matching a current observation with a memory of a prior observation of the same entity)