Not Yet, Still
adverb
This is the adverb version of 未, so it means the same thing: not yet, or still, depending on the context.
いまだ
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 it with this kanji, so here 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 今 (いま). Note that this word can also be read まだ. However, いまだ is often written in kanji, while まだ is almost always written in kana. So when you see 未だ, it's a safe bet to read it as いまだ!
未だ海外に行ったことが有りません。
I have never been abroad.
主人がどこにいるのか、未だ不明です。
It is still unknown where my husband is.
未だ、二百才まで生きた人はいないでしょう。
I bet no one has lived up to 200 years old.