To Get Close
To Approach, To Draw Near, To Near, To Bring Near
intransitive verb, godan verb
Because this word ends with an う sound, you can tell it's probably a verb. The kanji portion means near. The verb version of that is to draw near, to get close or to approach. Essentially, the general idea is that you're getting closer to something. You're becoming more nearby. You're approaching.
ちかづく
There's hiragana attached to this kanji, which means it's probably the kun'yomi reading (and it is). You've seen the kun'yomi reading via the word 近い. So, as long as you know that word, you should be able to read this one as well.
カメラマンが近づくとカメはにげてしまった。
When the cameraman approached it, the turtle ran away.
おれの女に近づくな！
Don't go anywhere near my girlfriend!
私達に今近づいてきているゾンビ、めちゃくちゃ私のタイプなんだけど。
Strange as it is, the zombie approaching us right now is actually my type.