from The Century Dictionary and Cyclopedia
- In a blottesque manner; with blot-like touches: as, to paint blottesquely.
Sorry, no etymologies found.
He found that his work in mathematics and classics was already some time in arrears, and a “test” he had sent to his correspondence Tutor during those troublous days after the meeting with Bonover in the Avenue, came back blottesquely indorsed:
Avenue, came back blottesquely indorsed: "Below Pass Standard."