In digital circuits, a bistable multivibrator that is capable of serving as one bit of memory (4-4)
I believe the answer is:
flip-flop
(Other definitions for flip-flop that I've seen before include "Flimsy sandal" , "Sandal held on by a toe-thong" , "Light shoe" , "Shoe held on by a toe-thong" , "Rubber-soled sandal" .)