what is slub
noun. verb. The definition of a slub is a roll of fiber used for spinning or an irregular place in yarn or fabric. An example of slub is a roll of alpaca wool yarn.Slub is defined as to draw out and twist a strand of fiber or textile for spinning.An example of slub is pulling a strand of wool to spin into yarn.oun. verb. The definition of a slub is a roll of fiber used for spinning or an irregular place in yarn or fabric. An example of slub is a roll of alpaca wool yarn.