dorsal/ventral - on the back/on the belly, where the belly is to the substrate, like a lizard or a fish
imbricate - stacked like tiles, descriptive of leaf arrangement
incubous - upper edge of each leaf overlaps the next leaf along the stem
succubous - lower edge of each leaf overlaps the next leaf along the stem
julaceous - doesn't mean anything you could guess! Look it up if you don't know :)
trigone - junction of three cells which may appear "inflated"
"Succubous" and "incubous" of course shouldn't be confused with "succubus" and "incubus", despite the fact that some of these liverworts look like they might be demons to ID!
I think I'll see what I have by way of photos to illustrate these terms. Should be able to come up with something I reckon.
From a Plagiomnium rostratum leaf (not a liverwort, but anyway...), here's a pattern of trigones:
|fat trigones, skinny cell walls|