carbon black, lampblack, soot, smut, crock -- (a black colloidal substance consisting wholly or principally of amorphous carbon and used to make pigments and ink)
crock -- (nonsense; foolish talk; "that's a crock")
crock, earthenware jar -- (an earthen jar (made of baked clay))
Overview of verb crock
The verb crock has 2 senses
crock -- (release color when rubbed, of badly dyed fabric)