Hate
Really Hate
Remember how 嫌い is to dislike? When that dislike is big, you really dislike it. That means you hate (or really hate) it.
だいきらい
The reading is the reading for 大, and the reading for 嫌い is like the one you learned with 嫌い in level 20.
コウイチはあなたのことが大嫌いなので、彼に代わってビエトがお会いします。
Mr. Viet will meet with you instead of Mr. Koichi because Mr. Koichi really hates you.