Science
noun
The study of science is plainly known as science.
かがく
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
かの女のせんもんは、科学です。
Her major is science.
日本は科学ぎじゅつというめんにおいてとてもすぐれています。
Japan is very advanced in the fields of science and technology.
我々に蚊除け剤を作らせてくれる科学は、本当に偉大だ。
Science is really amazing because it allowed us to make mosquito repellent.