platitudinarian
/ˌplatɪtjuːdɪˈnɛːrɪən/ /ˌplatɪtʃuːdɪˈnɛːrɪən/adjective
Characterized by platitude; tending to use platitudes.
noun
A person who utters or deals in platitudes.
Origin
Mid 19th century; earliest use found in Thomas Lynch (1818–1871), hymn writer and composer. From platitude + -in- + -arian, after e.g. latitudinarian, latitudinarian. With use as adjective compare slightly earlier platitudinary.