Horizontal Fall

Newly matriculated into Secret Rupicolous Society, Edmund read the longueurs describing the salient amenities, the descriptions of such trumpery and dreck on the shelves in the penetralia of the hypogeal (and believably petrous) bunker was the pis aller; Edmund was ready to abnegate his membership because of his tenacious probity.

matriculate (muh-TRIK-yuh-Layt) tr. & intr. v. To admit or be admitted into a group, especially a college or university. —n. (-lit, -Layt) One whi is admitted as a student to a college or university. —matriculation n.
So the summer after you're a high school senior and before you're a college freshman, you can describe yourself as a matriculate.

rupicolous (roo-PIK-uh-luhs) adj. Thriving among or inhabiting rocks.

longueur (loh(n)-G(OE)R) n. A dull and tedious passage or section (as of a book).
Long, drawn-out passages of books, parts of plays and movies, get a term? Why don't they just get edited out?

salient (SAY-lee-uhnt, SAIL-yuhnt) adj. 1. Projecting or jutting beyond a line or surface; protruding. 2. Strikingly conspicuous; prominent. 3. Springing; jumping. n. 1. A military position that projects into the position of the enemy. 2. A projecting angle or part. —saliently adv.
It seems to me you hear this word used in the second-definition sense rather than the first.

trumpery (TRUM-puh-ree) n. 1. Showy but worthless finery; bric-a-brac. 2. Nonsense; rubbish. 3. Deception; trickery; fraud.
You can be practicing trumpery while selling trumpery.

dreck (drek) n. Slang Trash, especially inferior merchandise. —drecky adj.

penetralia (Pen-ih-TRAY-lee-uh) pl. n. 1. The innermost parts of a building, especially the sanctuary of a temple. 2. The most private or secret parts; recesses: the penetralia of the soul.

hypogeal (Hy-puh-JEE-uhl) also hypogean (-uhn) or hypogeous (uhs) adj. 1. Located under the earth's surface; underground. 2. Botany Of or relating to seed germination in which the cotyledons remain below the surface of the ground. —hypogeally adv.

petrous (PET-ruhs) adj. 1. Of, relating to, or resembling rock, especially in hardness; stony. 2. Of or relating to the very dense, hard portion of the temporal bone that forms a protective case for the inner ear.

pis aller (pee zah-LAY) n. The final recourse or expedient; the last resort.
Is this the French name of Papa Roach's song?

abnegate (AB-ni-Gayt) tr. v. 1. To give up (rights or a claim, for example); renounce. 2. To deny (something) to oneself.

tenacious (tuh-NAY-shuhs) adj. 1. Holding or tending to hold persistently to something, such as a point of view. 2. Holding together firmly; cohesive. 3. Clinging to another object or surface; adhesive. 4. Tending to retain; retentive. —tenaciously adv. —tenaciousness n.

probity (PROH-bih-tee) n. Complete and confirmed integrity; uprightness.