Term: pathognomonic (often misspelled as pathognomic)
Literally meaning: “index for suffering/disease”
Origin: Anc Greek
παθο-/patho-(=prefix denoting “suffering”) > πάθος / pathos(=passion, sorrow, strong emotion)
+ γνώμων/gnomon(=judge) >γιγνώσκω/gignosko(=understand, know,
Pathognomonic is any sign that is characteristic for a particular disease on which a diagnosis can be made.