An example of something banal are boring knock-knock jokes that have been told many times before.
Origin of banalFrench from OFr, designating objects (such as ovens or mills) belonging to feudal serfs (hence common, ordinary) from ban, decree, legal control: see ban
Origin of banalFrench from Old French shared by tenants in a feudal jurisdiction from ban summons to military service of Germanic origin ; see bhā-2 in Indo-European roots.
Usage Note: The pronunciation of banal is not settled among educated speakers of American English, and several variants compete with each other. The pronunciation (bə-năl′), rhyming with canal, was preferred by 58 percent of the Usage Panel in our 2001 survey, while 28 percent favored (bā′nəl), and 13 percent said they used (bə-näl′), a pronunciation that is more common in British English. A number of Panelists admitted to being so vexed by the word that they tended to avoid it in conversation. Nonetheless, all three pronunciations should be considered acceptable.
(comparative banaler or more banal, superlative banalest or most banal)
From French banal, from Medieval Latin bannalis (“pertaining to compulsory feudal service, applied especially to mills, wells, ovens, etc., used in common by people of the lower classes, upon the command of a feudal superior; hence, common, commonplace”), from bannum (“command, proclamation”).