Alternative form of with one voice

(of vocalizing) In unison, together / (idiomatic, by extension, of expressing opinions by members of a group) In a mutually agreeing or like-minded manner; concordantly, unanimously.

(idiomatic, of two or more people) Having the same viewpoint, opinion, or attitude; in agreement.

(idiomatic) In one's opinion, from one's point of view.

(Ulster) An unpredictable person.

(calculus) a covector field

(slang, basketball) A basketball player who plays college basketball for a single year and then declares for the NBA draft.

(obsolete, nonce word) secret

(idiomatic, Northern England) Alone, on one's own.

Misspelling of one-sidedly.