This is the 496th most frequent Japanese word.
非常
"非常" (Hijou) means "emergency" or "extraordinary."
Here, 非常 (hijou) is used as a prefix meaning 'emergency', commonly seen in compound words like 非常口 ('hijou-guchi', emergency exit).
非常口から脱出してください。
Please use the emergency exit.
In this context, 非常に ('hijou ni') is an adverb meaning 'very' or 'extremely', enhancing the adjective following it.
今日は非常に面白い話が聞けました。
Today, I heard a very interesting story.
The term 非常 here functions as an adjective, meaning 'extraordinary' or 'unusual', describing actions.