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.
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.
それ以上、川に近づくな！
Don't get any closer to the river!
この犬は、大人の男が近づくと、立ち上って「ワン！」と言います。
This dog gets up and says "woof!" if an adult man approaches him.
来週、九州に台風が近づきます。
Next week, a typhoon will be approaching Kyushu.