Rare; to form hay into stacks or arrange something in a hay-stack shape.
Definitions
To stack dried hay into a tall pile for storage. They haystacked the freshly cut grass before the storm rolled in.
Synonyms
bank (hay)
heap up
pile up
stack up
Used chiefly attributively for resemblance in shape/appearance or to denote a search task over large data sets.
Definitions
Resembling or shaped like a haystack; thick, untidy, or bushy. After removing his helmet, his hair stood up in a wild, haystack mess.
Attributive: relating to the problem of locating a specific item within a vast collection of data. The programmer created a haystack search routine to locate anomalies in the log files.