se·mi·ol·o·gy also se·mei·ol·o·gy 
(sē′mē-ŏlə-jē, sĕm′ē-, sē′mī-)
(sē′mē-ŏlə-jē, sĕm′ē-, sē′mī-)n.
1.
a. The science that deals with signs or sign language.
b. The use of signs in signaling, as with a semaphore.
2. Symptomatology.
[Greek sēmeion, sign; see SEMIOTIC + -LOGY.]
se′mi·olo·gist n.