非同小可
Something out of the ordinary.
No small matter.
Not to be dismissed lightly.

eg：The discovery made by him is something out of the ordinary.

中英俚语俗语来源：元曲选·魔合罗：“人命事关天关地，非同小可。”

同义词：不可轻视 Not to be sneezed at.
反义词：平淡无奇 Nothing to write home about.