Quipu feature (4)
I believe the answer is:
knot
'quipu feature' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for knot that I've seen before include "Small sandpiper - fastening device" , "Unit of speed used at sea" , "Something tied" , "Shore bird, tangle" , "Air mile" .)