Flat
noun, な adjective
The kanji and the word are exactly the same with a little hiragana sticking out. Because the hiragana doesn't really indicate what it is, it's okay to assume that they share meanings as well.
たいら
Since this word is made up of a kanji plus some hiragana attached, 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: Something is very, very flat. Perhaps someone who doesn't eat much, like a model? Which model? Let's imagine it's Tyra (たいら) Banks.
あの山、平らですね。
That mountain is flat.
これは土を平らにするマシンです。
This is a machine that flattens the ground.
平らなところでもビー玉のレースはできますか？
Can I race marbles even on a flat surface?