The flakes of skin that fall off due to the action of vigorous bodily scratching. Can sometimes leave a trail similar to that of a snake shedding it's skin.
Oh my word check out the trail of firk coming off that guy, it's almost like it is snowing!
The verb firk is used in association with the preparation of food. To whisk. to whipp up to beat. It is also used as an exhortation. For example 'beat it'.
They reallybegan to get on my nerves so I told them to firk off