(noun)
a thread or wire made of gold or silver, used for edging, bordering, or embroidering something;
e.g. The fabric had a purl border of a delicate pattern.
(verb)
to knit using a stitch in which a needle is passed through the front of a loop on the other needle (purl stitch);
e.g. He knew he had to purl one stitch and knit the next to make the fabric correctly.
(verb)
to use gold or silver thread on order to embroider something, especially along an edge or border;
e.g. It will be a slow task to purl the garment in the required pattern.
(noun)
a gentle swirling movement/flow, accompanied by a babbling or murmuring sound, or a stream of water that moves/flows in this way;
e.g. The river slowed to a purl when it entered the valley.
(verb)
to have a gently swirling movement/flow, accompanied by a babbling or murmuring sound;
e.g. We heard the stream purl and knew we were going in the right direction.