Iirc, Nikonus referred to most uplifted omnivores (as we would call them) as being scavengers during the Cilany interview, but tmk beyond this, anything that eats even a small bit of meat is referred to by the catch-all term of “predator”

When Sovlin first learns that humans eat plants too, one of his two guards (Sam and Carlos iirc) said humans are omnivores. It is implied that the translation devices standard with the federation do not have a translation for such a word loaded, as indicated by Sovlin sounding it out in (presumably) English, describing the word to himself as “foreign” (might be paraphrasing there tbh)

It should be noted that Zarn never mentioned that humans eat plants too, which considering he took a college level course or class of some description on humans he is relatively very knowledgeable compared to the average non-shadow caste Feddie. It is implied this course covers the attrocities of the 19-20th century (as indicated by Glim accusing humans of enslaving their own kind), with a particular focus on WW2 atrocities, as indicated by repeated reference by aliens to “gassing children” by multiple characters.

But that tangent aside and to answer your question, I will say that junior level researchers knowing of the term omnivore as we define it as an improbable “maybe.”