anyone and everyone; anybody at all
Used to indicate that an action or state applies to people in general, without specifying individuals. Often appears in contexts like '誰彼となく話しかける' (talks to anyone and everyone).
彼は誰彼となく親切に接する。
He treats anyone and everyone kindly.
誰彼となく声をかけて回った。
I went around calling out to anybody at all.
誰でも simply means 'anyone', while 誰彼となく emphasizes the lack of discrimination or the broad, random nature of the people involved.
Standard kanji-kana mixed spelling.
Variant with かれ in kana; less common but still seen.
Rare spelling using the kanji 無 for なく.
Mixed kana-kanji spelling; very rare.
A set phrase combining 誰 (who) and 彼 (that person) with the particle と and the negative form of ある (ない → なく), literally 'without distinguishing who or that person'. The exact historical derivation is uncertain, but it has been used since at least the Edo period.