de·fer·ves·cence (dē'fər-věs'əns) n. The abatement of a fever.
[From Latin dēfervēscēns, dēfervēscent-, present participle of dēfervēscere, to stop boiling, cool off : dē-, de- + fervēscere, to grow hot, inchoative of fervēre, to be hot, boil; see bhreu- in Indo-European roots.] de'fer·vesce' (-věs') v., de'fer·ves'cent adj.