A "knit cardigan" refers to a type of sweater that is made using a specific technique called knitting. It has buttons or a zipper on the front and is usually quite warm and comfortable to wear.
I decided to wear this oversized chunky knit cardigan with my look as it is not only cozy but it creates an effortless sporty chic look. (fanciersworld.com)
You generally wouldn't think to pair a heavy knit cardigan with shorts, but when worn with a crisp white woven — it works. (samcperry.com)
I wore some with a vintage dress and cable knit cardigan in this post last year. (vintage-frills.com)