adverb, adverb taking the 'to' particle, noun or participle which takes 'suru'
tediously; repeatedly; at great length
Describes explaining, complaining, or insisting in a long-winded, repetitive, and tiresome way. Often used with verbs like 言う, 説明する, or 文句を言う.
彼はくどくどと同じ言い訳を繰り返した。
He tediously repeated the same excuse over and over.
I understand without you explaining at great length.