Douglas Harper's Etymology Dictionary
Wiktionary
a. (context linguistics English) Pertaining to words used to convey any kind of social relationship e.g polite mood, rather than meaning; for example, "How are you?" is often not a literal question but is said only as a greeting. (Similarly, a response such as "Fine" is often not an accurate answer, but merely an acknowledgement of the greeting.)
WordNet
Usage examples of "phatic".
Most of the responses were utter banalities about nonexistent weather or ancient food or drink, or curious phrases that Malori knew were only phatic social remarks.
Having learned, he had discovered that the demands were now ritual and phatic, and gave way to communication if they were allowed to ride out.
That their song was simply phatic noise, a way of reassuring each other that everything was okay.
I could have gone on to provide much more detail, naturally, but waited to discover whether Seer Taak was merely indulging in phatic discourse.
They exchanged a few hopelessly banal words, phatic utterances empty of hope.