---
title: defs
---
A string that will be rendered
as [the defs section](https://developer.mozilla.org/en-US/docs/Web/SVG/Element/defs) of
the SVG document.
The defs attribute is where plugins will add additional snippets.
```svg
/* svg.defs will be inserted */
```
###### Add, but don't overwrite
When adding your own defs, it's important not to
overwrite this property, but rather add your own.
In other words, do this:
```js
svg.defs += myDefs;
```
and don't do this:
```js
svg.defs = myDefs;
```