Meal, Cooked Rice, Food
noun
The kanji and the word are exactly the same. That means they share meanings as well. It also refers to cooked rice, because you gotta eat cooked rice with every meal, so it's basically synonymous with "meal" itself. This word has a slightly gruff feel to it so it's used mostly in informal situations.
めし
Since this word is made up of a single kanji, it should use the kun'yomi reading. When learning the kanji, you didn't learn that reading, so here's a mnemonic to help you with this word: You're eating a meal... MMmm, delicious! What are you eating? Well, it's a Mesh (めし) net. Taste the mesh net. It tastes terrible. This is a bad meal. Feel it in your mouth. It's weird and meshy.
今度、飯でも行かない？
How about we go grab a meal sometime?
ねー、飯まだ？ハラペコなんだけど。
Hey, still no food? I'm starving.
この社員は三度の飯より仕事をするのが好きです。
This employee prefers working to eating three meals a day.