などなど

などなど
expression
and so on; etcetera; etc.
1. and so on; etcetera; and more
A casual emphatic repetition of など, used at the end of a list to indicate that there are more items. More emphatic and conversational than a single など, suggesting that the list could go on considerably.
りんご、バナナ、みかん、などなど。
Apples, bananas, oranges, and so on.
料理(りょうり)掃除(そうじ)洗濯(せんたく)、などなど、やることが(やま)ほどある。
Cooking, cleaning, laundry, and so on — there's a mountain of things to do.
旅行(りょこう)準備(じゅんび)で、パスポートの確認(かくにん)、ホテルの予約(よやく)荷造(にづく)り、などなど、やることがたくさんあって大変(たいへん)だ。
With travel preparations — checking my passport, booking a hotel, packing, and so on — there's so much to do that it's overwhelming.

USAGE:
More casual and emphatic than a single など or (など). Often used in spoken Japanese and informal writing. Implies that the speaker could continue listing items but chooses not to. Can convey a sense of being overwhelmed by the quantity.

SIMILAR WORDS:

  • など: The basic form, neutral in register. Can be used formally.
  • 等々(とうとう): The formal/written equivalent of などなど. Used in documents and formal speech.
  • とか: Casual particle for listing examples, but used between items rather than at the end of a list.

TONE:
Conversational and slightly playful. Not appropriate in formal writing or business documents, where (とう) or 等々(とうとう) would be preferred.