xenomorph
An Ars Technica article from 2014 explains that the word “xenomorph” in Aliens is a generic term and not a specific name for that specific species.
Commenters point out that the exhaustively argued conclusion that the article comes to is exactly what they had assumed to be true from watching the movie. Nonetheless, I admire the geeky thoroughness of the author.
Content warning for a quote from Aliens that includes a sometimes-racialized misogynist term.