Source : Webster's Revised Unabridged Dictionary (1913)

Coarse \Coarse\, a. [Compar. {Coarser}; 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;
      coarse bread.

   2. Not refined; rough; rude; unpolished; gross; indelicate;
      as, coarse manners; coarse language.

            I feel Of what coarse metal ye are molded. --Shak.

            To copy, in my coarse English, his beautiful
            expressions.                          --Dryden.

   Syn: Large; thick; rough; gross; blunt; uncouth; unpolished;
        inelegant; indelicate; vulgar.