dt and dd elements have to be wrapped in a parent dl element.
Why dl items must be wrapped in dl elements?
Users of assistive technologies such as screen readers need that web pages' elements are properly announced: therefore, <dt> and <dd> elements have to be wrapped in a parent <dl> element.
How this SeoChecker audit fails
If dl items aren't wrapped in <dl> elements, SeoChecker will notify it.
How can I fix orphaned definition list items
You need to use dl elements around the list, with dt elements that mark every term and dd elements related to every definition.
Have a look at the example below:
<dd>Extra grip for uneven, natural surfaces, such as forest trails.</dd>
<dd>Extra cushioning for hard surfaces, such as sidewalks and roads.</dd>