semiology

The science that deals with signs or sign language.

The use of signs in signaling, as with a semaphore.

Symptomatology.

The logical theory of signs, of the conditions of their fulfilling their functions, of their chief kinds, etc.

The use of gestures to express thought.

The sum of scientific knowledge concerning morbid symptoms and their pathological significance; symptomatology; semiotics.

Semiotics, the study of signs.

(philosophy) a philosophical theory of the functions of signs and symbols