I took that as they have encountered other species before, just nothing like the creature from the Alien franchise. The term xenomorph is just used to describe any creature not found on Earth, aka aliens.

This is backed by an earlier comment made during Ripley's hearing with the company:

Insurance attorney: Are there any species like this hostile organism on LV-426? ECA representative: No, it's a rock. No indigenous life.

Which would indicate they have encountered other aliens, just not this Alien.

The creature was named both Alien and Xenomorph because that's what it is, but came to define the names and took "ownership" of the names, if you will.

[–] magnetosphere@kbin.social 4 points 1 year ago

Okay. Thank you! I like the “xenomorph is a generic term” explanation. It works with the way people actually use language.

[–] octoperson@sh.itjust.works 1 points 1 year ago

Alien is a stupid name for an alien when you stop to think about it. Just like with the creature in Frankenstein, people are going to grab at any alternate name presented, cos it's just too awkward to talk about otherwise.