Immense, Tremendous, Enormous
noun, な adjective
Another way to say something is very big is to say it is immense or enormous.
じんだい
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
大型台風が甚大な被害をもたらした。
An immense typhoon brought on serious damage.