noun, の adjective
The kanji and the word are exactly the same. That means they share meanings as well.
Since this word is made up of a single kanji, it uses the kun'yomi reading. You haven't learned this reading yet, so here's a mnemonic to help you:
Imagine hearing someone to your left saying, "Hi Da'ri!" (ひだり) which is supposed to be "Hi There," or "Hi Dearie." You turn left and there's no one there. You hear it again, "Hi Da'ri!" Keep turning to the left until you find the person saying hi to you.
The left contact lens is missing.
The entrance is the door on your left.