afternoon is arriltä

arriltä = afternoon (noun) (some things Google found for "arrilta": a rare term; a rare last name; a very rare 19th century feminine first name; name of an Australian aboriginal manhood initiation rite; bad OCR of texts featuring the Spanish word arriba which means up)

Word derivation for "afternoon" :
Basque = arratsalde, arrats (early evening) + -alde (proximity)
Finnish = iltapäivä, ilta (evening) + päivä (day)
Miresua = arriltä

Both the Basque and the Finnish words start with with words meaning evening. My Miresua word is merely an alphabetic scramble, not a compound. I used the letters in common and the letters duplicated within each word. By the way, my Miresua word for evening is irtas.

This is a new word. Somewhat surprisingly, it doesn't appear in Alice's Adventures in Wonderland.