platitudinarian UK /ˌplatɪˌtjuːdɪˈtɛəɹi.ən/US /ˌplætɪˌtudəˈtɛɹi.ən/ noun1 •One who uses many platitudes in speaking or writing.Sir Culling was an extreme Low Churchman, an Exeter Hallite to the backbone, and the head and front of the Platitudinarian Party. — 1894 formsplatitudinarians