All of these terms are used in fairly recent descriptions of new species of wasps. A new published description is required for a new species to be valid. Right now that description, as required by the Zoological Code, must be text. Historically these texts do not adhere to any real rules of language (obviously! Unenlarged is not even a 'real' word according to Websters). A person could be as loose or florid as they desire with their descriptions, creating a lot of variation in word usage in descriptions of species.
Great by Platyscelio striga image by Norman F. Johnson & Charuwat Taekul with enlarged antennal segment
So if a person was describing the antenna in the image above he/she could say:
Antennal segment is rather large.
Antennal segment is enlarged.
Antennal segment is larger than the proceeding segments.
Antennal segment is the largest.
Antennal segment is large.
Proceeding antennal segments unenlarged. (Only one author used this word - lets just push this under the rug and forget it ever happened?).
We may only need the word root. Large. Comparisons seem to be the answer and we can remove all terms except the root terms. If we said: Second antennal segment large compared_to proceeding segments we would know that segment is the largest segment. Lets try an even more detailed example. Second antennal segment large compared_to third antennal segment. Third antennal segment large compared_to proceeding antennal segments. We then would know that the third segment is actually of medium size.
Words like 'rather' are nice but lack any real meaning and could be ignored. Or does 'rather large' actually mean 'its kinda, sorta large compared to all the other wasps but I wouldnt necessarily call it large". That doesnt sound like a word to use in describing a decisively new species.
Who cares? Well only a few people right now but we are moving away from human descriptions of new species. It is a bit sad that we will loose some of the 'authors touch' for the sake of automation. I have the same feeling about it as I did when the NOAA weather radio man in my hometown turned into a robot voice. I was never excited again about a severe thunderstorm warning.