Obstruent \Ob"stru*ent\, a. [L. obstruens, p. pr. of obstruere. See {Obstruct}.] Causing obstruction; blocking up; hindering; as, an obstruent medicine. --Johnson. Obstruent \Ob"stru*ent\, n. Anything that obstructs or closes a passage; esp., that which obstructs natural passages in the body; as, a medicine which acts as an obstruent.