さもなくば

conjunction

otherwise; or else; if not

Conjunction used to present an alternative or consequence, often with a warning or strong suggestion. Common in both spoken and written Japanese.

• 急いそいでください、さもなくば遅おくれますよ。

  Please hurry up, otherwise you'll be late.

• もっと勉べん強きょうしなさい。さもなくば試し験けんに落おちるよ。

  Study harder. Or else you'll fail the exam.