by chance

思いがけない、偶然、偶々、ひょっこり

by chance の類語

accidentally, somehow, by luck, hit or miss, chance, at random, incidentally, sporadically, irregularly, by accident, randomly, haphazardly, casually, perchance, fitfully, in some way, random, spasmodically, indiscriminately, carelessly, for some reason, unexpectedly, at haphazard, somehow or other, in spots, by good fortune, by fits, by hazard, at intervals, erratically, by a fluke, unpredictably, in snatches, by snatches, sloppily, as it chanced, haply, promiscuously, fortuitously, capriciously, desultorily, unsystematically, circumstantially

by chance の反意語

regularly, deliberately

例文

• By chance, I met her in the street.
  偶然、私は道端で彼女に会った。
• By chance I met my ex-girlfriend in Portugal.
  偶然、ポルトガルで前の彼女に会った。
• I met her by chance.
  偶然、彼女にあったんだ。

by chance の言い換えを探すには

by chance（思いがけない）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。