There’s still never been a person who’s lived to two hundred years old.
I’m still jet-lagged.
I’m not sure if I got the job yet. It seems like they still have to interview twelve other applicants.
This is the adverb version of 未, meaning it means the same thing: not yet.
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:
Someone's telling you "not yet... not yet.... not yet..." you have some food on your nose, but you're not allowed to eat it until your ma says it's okay. "Not yet... Not yet..." Why would your mom treat you like a dog like this? Oh well... maybe she'll let you eat the food soon, at least.