Synonymize

Syn*on"y*mize (?), v. t. [imp. & p. p. Synonymized (?); p. pr. & vb. n. Synonymizing (?).] To express by a synonym or synonyms; to give the synonym or synonyms corresponding to.

This word "fortis" we may synonymize after all these fashions: stout, hardy, valiant, doughty, courageous, adventurous, brave, bold, daring, intrepid.