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repetitious; long-winded; tedious; wordy; verbose; insistent; importunate
heavy (taste); (overly) rich; strong; cloying
gaudy (colour, design, etc.); loud
彼の説明はくどくて聞いていられない。
His explanation is so verbose I can't stand listening.
くどい味付けよりあっさりした料理が好きだ。
I prefer light dishes over heavy-flavored ones.
同じことを何度も言うのはくどいのでやめて。
Stop repeating the same thing, it's tedious.