Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you: If you are as mad as a hatter you'll need to work very hard to regain your sanity. You know The Hatter from Alice in Wonderland? Imagine how hard he would have to work to be considered "normal".
I had to labor through the day with a headache and an empty stomach.
I'm studying Japanese to work in Japan.
"Would you like to come read Tofugu articles on Friday?" "I’d like to but I have to work late Friday night." "That’s too bad. Maybe some other time."