1. 平凡的：platitudinize 说平凡的话 | platitudinous 平凡的 | Plato 柏拉图

2. 陈腐的：platitude平凡,陈词滥调 | platitudinous陈腐的original | pliable a.柔软的,易曲折的ply 折,弯

3. 平凡的/陈腐的：platitudinize /说平凡的话/ | platitudinous /平凡的/陈腐的/ | platitudinously /平凡地/

4. 平凡的; 陈词滥调的; 陈腐的 (形)：platitude 单调, 陈腐, 平凡 (名) | platitudinous 平凡的; 陈词滥调的; 陈腐的 (形) | Plato 柏拉图 (名)

adj

1. dull and tiresome but with pretensions of significance or originality

e.g. bromidic sermons

Synonym: bromidiccornyplatitudinal