The Collaborative International Dictionary
Crocking
Crock \Crock\, v. t. [imp. & p. p. Crocked (kr[o^]kt); p. pr. & vb. n. Crocking.] To soil by contact, as with soot, or with the coloring matter of badly dyed cloth.
Wiktionary
crocking
vb. (present participle of crock English)