The Collaborative International Dictionary of English v.0.48:
Coarse \Coarse\ (k[=o]rs), a. [Compar. Coarser
(k[=o]rs"[~e]r); superl. Coarsest.] [As this word was
anciently written course, or cours, it may be an abbreviation
of of course, in the common manner of proceeding, common, and
hence, homely, made for common domestic use, plain, rude,
rough, gross, e. g., "Though the threads be course."
--Gascoigne. See Course.]
1. Large in bulk, or composed of large parts or particles; of
inferior quality or appearance; not fine in material or
close in texture; gross; thick; rough; -- opposed to
fine; as, coarse sand; coarse thread; coarse cloth;
2. Not refined; rough; rude; unpolished; gross; indelicate;
as, coarse manners; coarse language.
Of what coarse metal ye are molded. --Shak.
To copy, in my coarse English, his beautiful
Syn: Large; thick; rough; gross; blunt; uncouth; unpolished;
inelegant; indelicate; vulgar.