What does Crocking mean?

The term used when dye rubs off fabric and on to skin or another fabric.

Heddels explains Crocking

Crocking usually occurs in heavily dyed fabric, such as raw denim. Compared to “bleeding”, where the dye comes into contact with liquid; crocking occurs when the dye is physically rubbed off.

Crocking is one of the processes that helps give raw denim its personality and is the cause for fades and atari on creases, seams, and any other worn areas.