The politician has repeatedly denied any involvement in the scandal.

repeatedly 是副词，由动词 repeat（重复）加上后缀 -ed 和 -ly 构成。repeat 意思是"重复"，-ed 表示完成或被动，-ly 将形容词变为副词。repeatedly 表示"多次地、反复地"，强调动作的重复性。