knit up
Also found in: Dictionary.
knit up
To produce something by knitting, often with little effort. A noun or pronoun can be used between "knit" and "up." Can you believe Grandma just knitted up this sweater for me? It would take me weeks to make something like this!
knit up
v.
To create something by knitting, especially quickly or easily: I knitted up some mittens for my grandchildren. I knitted some hats up for the church sale.