The word "quirky" indicates something that is strange, peculiar, or unconventional. Antonyms for "quirkiest" are words that indicate qualities that are conventional, normal or predictable. These include terms like ordinary, common, mainstream, traditional, and typical. While quirky denotes originality and uniqueness, its antonyms, such as banal or mundane, denote a lack of imagination or creativity. If something is described as classic or customary, it suggests that it is tried and tested, and therefore a safe choice. Expressions like predictable, average, standard, or cliched carry a sense of conformity, lacking the peculiarities or oddities often associated with quirky.