<dl> elements must only directly contain properly-ordered <dt> and <dd> groups, <script>, <template> or <div> elements
How to Fix the Problem
  Check that your definition list has only dt and
  dd elements. Furthermore, make sure these are properly ordered,
  dt should precede dd elements.
  Definition list items require dl elements around the list,
  dt elements for each term, and dd elements for each
  definition. Each set of dt elements must be followed by one or
  more dd elements. Ensure that your definition lists follow these
  specifications and mimic the example below.
Example
<dl>
 <dt>Coffee</dt>
  <dd>Black hot drink</dd>
 <div>
  <dt>Milk</dt>
   <dd>White cold drink</dd>
 </div>
</dl>Why it Matters
Screen readers have a specific way of announcing definition lists. When such lists are not properly marked up, this creates the opportunity for confusing or inaccurate screen reader output.
  A definition list is used to provide the definitions of words or phrases. The
  Definition List is marked up using the dl element. Within the
  list, each term is put in a separate dt element, and its
  definition goes in the dd element directly following it.
Rule Description
  Definition lists (dl) must contain only properly-ordered
  dt and dd groups, div,
  script, or template elements.
The Algorithm (in simple terms)
Ensures that all dl elements are structured correctly.