axiomatic
adjective /ˌæksiəˈmætɪk/
/ˌæksiəˈmætɪk/
[not usually before noun] (formal)- true in such an obvious way that you do not need to prove it
公理；不证自明 - It is axiomatic that life is not always easy.
生活并不总是一帆风顺，这是明摆着的事实。
词源late 18th cent.: from Greek axiōmatikos, from axiōma ‘what is thought fitting’, from axios ‘worthy’. - It is axiomatic that life is not always easy.