Comment by gucci-on-fleek

> I've sometimes heard "orphan" used to represent a single word left alone on its own line at the end of a paragraph, but the terms are often confused and Carter could have used "widow" in that sense.

This is an acceptable use of the term "widow". From the Oxford English Dictionary [0]:

> A short line of text (usually one consisting of one word or part of a word) which falls undesirably at the end of a paragraph, esp. one set at the top of a page or column.

But there are dozens of contradictory meanings for "widow" and "orphan" [1], so the definition that you gave isn't wrong either.

[0]: https://doi.org/10.1093/OED/1579263894

[1]: https://tug.org/TUGboat/tb43-1/tb133chernoff-widows.pdf#subs... (Disclaimer: I'm the author of this article)