this and that; something or other; one thing or another
Used to refer vaguely to various unspecified things, often in contexts of doing or talking about multiple miscellaneous matters.
I was busy with this and that, so my reply was late.
He always finds one thing or another as an excuse to skip meetings.
Standard kanji-kana mixed spelling.
Alternate kanji spelling using 彼; less common.
Reduplicative phrase combining 何か (something) and かにか (an old interrogative pattern); the exact derivation of かにか is uncertain, but it likely served as a rhyming or emphatic counterpart.