<p>I have done this:</p>

<pre><code>$ z() { echo 'hello world'; }
</code></pre>

<p>How do I get rid of it?</p>

```
```
unset -f z
```
```
Will unset the function named z.  A couple people have answered with:
```
```
unset z
```
```
but if you have a function and a variable named z only the variable will be unset, not the function.