[pre.cur.sor] n [ME precursoure, fr. L praecursor, fr. praecurrere to run before, fr. prae- pre- + currere to run--more at current] (15c) 1 a: one that precedes and indicates the approach of another b: predecessor
2: a substance, cell, or cellular component from which another substance, cell, or cellular component is formed syn see forerunner -- pre.cur.so.ry adj