Unit of text with inline number-less bold heading

Question

Is there a name to specifically refer to a unit of text that starts with an inline number-less heading in bold followed by one or more paragraphs as below? If there is, what is it called?

About Blah Blah Blah Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Answer 1

What it's called depends on why it's bolded.

In papers conforming to APA style, the third-level headings are bolded, inline, and number-less. The corresponding unit of text could be called a subsection or a third-level section. This is probably the terminology that you are looking for.

In math papers, you will often see theorems, lemmas, corollaries and definitions set off this way; for example:

Pythagorean Theorem: The square of the hypoteneuse of a right triangle is equal to the sum of the squares of the other two sides.

In this case, the unit of text could be called a theorem statement.

I don't see any need for a word that covers both of these possibilities.

Answer 2

A sequence of such sections is sometimes referred to as a definition list (w3.org - HTML). Each entry in the list is thus a definition-list entry.