Knowledge
Information, Understanding, Rules
noun
What does your heart want to acquire above all other things? Knowledge! That's why you're here isn't it? Dig deep and see that all your heart wants is more information and understanding of Japanese to be happy.
こころえ
The readings for this word are both kun'yomi readings. You've learned both of these readings by now so you should be able to read this on your own.
先輩が就職活動の心得を教えてくれました。
My senpai passed on his knowledge about job hunting.