subhead

[suhb-hed]

noun

a title or heading of a subdivision, as in a chapter, essay, or newspaper article.
a subordinate division of a title or heading.
the immediate subordinate of the president or other head of an educational institution.

Also sub·head·ing (for defs 1, 2).

Origin of subhead

First recorded in 1580–90; sub- + head

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

To be fair, the subhead was later modified after I demanded via Twitter that it be so.
Peter Beinart’s Bias Against Me, Cory Booker, and Israel
Rabbi Shmuley Boteach
June 14, 2013

Tom's part in the affair was told in a couple of paragraphs under a subhead.
The Walking Delegate
Leroy Scott
All this is done, even where the saving under one subhead more than counterbalances the excess under another in the same vote.
The Government of England (Vol. I)
A. Lawrence Lowell

"smaller heading or title in a book, chapter, newspaper, etc.," 1875, from sub- + head (n.) in the sense of "heading, headline."