assumption

/ə-ˈsəm(p)-shən/

Middle English, from Late Latin assumption-, assumptio taking up, from Latin assumere seeassume

noun

  1. a taking to or upon oneself

  2. the act of laying claim to or taking possession of something

  3. an assuming that something is true

the assumption of a new position

noun

  1. self-conceit

idiom

  1. as though one knows : in the belief

We are operating on/under/with the assumption that the loan will be approved.