If possible, can you give a little more context. Because 'Knick' (in my mind) refers to The New York Knicks basketball team. 'Knick' isn't a word, but a word shortened (knick = Knicknerbookers).
To Knick = To curtsy slightly. Something women do (especially back in the early days), usually if wearing a skirt. Men don't curtsy usually, men would bow.
In this sentence; Both women slightly curtsy to each other as a polite gesture. \
Hope this helps!!
This word is not used much, most of the time, we would just use 'curtsy'