Frequency
Frequent Occurrence
noun, する verb
Something that frequently departures has much frequency and is a frequent occurrence. Oh, that? Yeah, it departures with much frequency.
ひんぱつ
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
みんな、頻発する地震に、ストレスが溜まりに溜まっているんだよ。
Everyone is extremely stressed out with these repeated earthquakes.