Various fenestral things (continued)

... and as it turns out, some of those are actually words-in-use.

Circumfenestrate adj. is a biological term apparently only used to describe nematodes of genus Heterodera; it refers to the structure of the vulval cone (whatever that is), meaning that said cone is a single opening. It contrasts with the adjective ambifenestrate, which I hadn't even imagined; this latter means that there is a "vulval bridge" across the vulval cone, dividing it into two openings.

Some sources also appear to use the terms bifenestrate (where the vulval bridge sufficiently wide that the two openings appear distinct) and semifenestrate (either ambifenestrate or bifenestrate); these consider semifenestrate to contrast with circumfenestrate, and ambifenestrate to be limited to narrower vulval bridges. I think what's happened is that the older ambi-/bi- distinction has fallen to the wayside, being somewhat subjective, so that ambifenestrate has taken on the meaning that semifenestrate used to have; but I am not a nematologist of any stripe, and do not have access to the sort of scientific journals and references that I would need in order to test that hypothesis.

Interfenestrate is in use, interestingly, only as a verb, and at that apparently a back-formation from the noun form interfenestration, an architectural term meaning the space between windows. (Verb use citation here, where it is used, without explanation, to mean to place windows between.) This is related to fenestration, the act or process of adding windows to a building or schematic, whence comes the verb fenestrate by backformation.

Of course, fenestrate as an adjective, rhyming with the other adjectives and meaning windowed, is also in use.

(These are all undeniably words, rather than mere protologisms, as they are used in sentences without explanation or humor and are immediately understood by people other than the writer.)