That is not an idiom. It means just what it says. You need a medical dictionary to look up medical conditions, not an idiom dictionary.
I think by idiom, you may be asking what type of language is represented by the phrase "inflammation of nictitating membrane." That phrase is typical of medical or scientific terminology rather than common or lay language.
"To be" is not an idiom - it's a verb.
The idiom "apple shiner" means the teacher's pet.
Pest is not an idiom. It's a word.
My Favorite IDIOM Is, When Pigs Fly.
It is actually an idiom.
The nictitating membrane is the transparent layer the covers the outside of a frogs eye. Frogs have a so-called Nictitating membrane, which they can slide over their eyes for protection. They do this while jumping and swimming.
The membrane is. SOME problems with it are too.
The nictitating membrane.
Nictitating membrane
Nictitating Membrane
depends on the species.
The nictitating membrane is part of a frog's eye. It is just above the lower lid and acts as a protective third eyelid.
It's called the Nictitating membrane
A nictitating membrane The nictitating membrane is the THIRD eyelid, the SECOND eyelid that you asked about is just that, the eyelid, just like in humans
With the nictitating membrane, which keeps it moist
The color of the nictitating membrane, also known as the third eyelid, varies among different species. In many animals, it can range from translucent to white or pinkish in color.
nictitating membrane