Today's word is "niau (to suit; to match well)". It is written with a combination of two kanji characters: "ni," "a" and the hiragana "u." "Niai no" is an adjective, which means, "well-matched." "Niawanai" is the negative form, which means, "unworthy; ill-matched." Here are some examples.
* Sono kamigata yoku niau ne. --- You look nice with that hairstyle.
* Sono e wa kono heya ni niawanai. --- The picture does not suit the room.
* Karera wa niai no fuufu da. --- They are a well-matched couple.