I hadn't dogeared any pages on my initial run-through of pages 5-50, but I went back and re-re-read them last evening. Turns out there were a couple dozen of new words in there.
Words I Didn't Know (p. 7-11)
"A hand trails over the gunwale and he lies athwart the skiff"
6. athwart (7)- obviously some sort of directional term. Yep, means across.
"Glancing up at these cathedraled vaultings with their fossil woodknots and pseudomorphic nailheads in gray concrete, drifting"
7. pseudomorphic (7)- Blogger.com tells me there are five words misspelled in this fragment of a sentence. I could parse together an idea of that this word meant. Pseudo - fake, morphic - form. Yeah, a fake form. It's also a geological term; a mineral that has the crystalline form of another mineral rather than the form normally characteristic of its own composition. That's probably more close to what he meant.

This is a pseudomorphic agate. Neat.
"...past warehouses of galvanized and corrugated tin set in flats gouged from the brickcolored earth where rhomboid and volute shapes of limestone jut..."
8. volute (9) - a shape, spiraled.

Looks like this to your left.
Suttree watches a body being pulled from the river. The man has apparently committed suicide.
"A pale incruent wound."
9. incruent (9) - a bloodless wound. Yeah, that happens when you're in the river a while I guess.
Suttree strikes up a conversation with 'Joe' (10).
J: Are you still fishin?
Yeah.
What made you take that up?
I dont know, Suttree said. It seemed like a good idea at the time.
A nice little summation of why Sut leads the life he does. He moves on to deliver a catfish to a fellow derelict. The man's cooking potatoes for dinner in a hubcap.
"Arched sumac fronds quivered in the noon warmth and pigeons squabbled and crooned in the bridge's ribbed spandrels."
10. spandrels

I'm guessing these are like trestles? Oh, not really. Close though. They're the spaces above arches.
Next up, a visit from Uncle John. Consequently, we learn a little about Suttree's past.