Gist
Principle
noun
The point of something is the gist and principle of it. So, what's the gist of this vocab word? It's gist as well.
The reading is the same as the word 胸 (chest). So, the gist of your body is your chest (it's at the center, and holds everything together, right?). That's why these words are both read as むね.
先生には、家庭の方針として、主人と私は子どもにそうした漫画は読ませたくないと思っているという旨を伝えました。
I explained the gist of our family policy and how my husband and I don’t want to let our kid read comic books to the teacher.