Something is taken for granted or considered natural and obvious.
当然应当如此。按道理应当这样。
隋·王通《文中子·魏相篇》非辩也，理当然耳。”
He thought it was only natural that he would get the promotion.
Learn the next connected idiom: 理所当然 (lǐ suǒ dāng rán) → 燃眉之急 (rán méi zhī jí)
Want to explore more random idioms? Try our 🎲 Chinese Idiom Generator