What defines them is the function, not the meaning they might conjure in a communicational context.
In this experience, two aspects of language come under scrutiny: the epistemological and the communicational.
The communicational status refers to language as a medium for sharing knowledge.
late 14c., from Old French comunicacion (14c., Modern French communication), from Latin communicationem (nominative communicatio), noun of action from past participle stem of communicare "to share, divide out; communicate, impart, inform; join, unite, participate in," literally "to make common," from communis (see common (adj.)).
communication com·mu·ni·ca·tion (kə-myōō'nĭ-kā'shən)
The exchange of thoughts, messages, or information, as by speech, signals, writing, or behavior.
An opening or a connecting passage between two structures.
A joining or connecting of solid fibrous structures, such as tendons and nerves.