as one

異口同音、同体に、翕然、一丸となって

as one の類語

in unison, together, all together, with one voice, hand in hand, jointly, unanimously, in chorus, with one accord, concurrently, back to back, as one man, simultaneously, collectively, mutually, in concert with, one and all, to a man, at once, on all hands, harmoniously, at a clip, shoulder to shoulder, at one time, in harmony, in a chorus, at the same time, all agreeing, hand in glove, without contradiction, in common, cooperatively, on the beat, in agreement, in phase, communally, in partnership, with one consent, conjointly, in harmony with, in sync, shoulder, concertedly, in concord, synchronously, nem con, by acclamation, corporately, cheek by jowl, concordantly, nemine contradicente

as one の言い換えを探すには

as one（異口同音）の類語・言い換え（パラフレーズ）を、日本語訳つきで関連度順に並べています。英作文の語彙を増やしたいとき、長文読解で本文と選択肢の言い換えを見抜きたいときに使えます。