"Does not happen!" -- pg. 73.
The author has Teppic using crampons to climb walls. I've seen this discussed about another author, and someone on a forum said they looked in the OED to find that crampon was an archaic word for a sort of piton. Maybe. I think Prachett should have gone with piton.
mutton avec no talking (pg. 93) -- It's french, means "with". Should have known this from the song lyric Voulez-vous coucher avec moi (ce soir)? from that Labelle song.
stack of wood licker wicker hurdles (pg. 50) -- On a Terry Prachett forum there is some discussion of this. Possibly a printer's error, in the Transworld edition the phrase is "wood like".
Obloquy (pg. 23) -- The condition of one that is discredited.
Dovecote (pg. 103) -- A small compartmented raised house or box for domestic pigeons.
benison (pg. 58) -- A spoken blessing.
a shonky shop (pg. 74) -- A poor or dubious quality.
the university's bledlows (pg. 73) -- The author is credited with definition it as a proctor.
pounces (pg. 268) -- from Word of the Day "600 years ago only the rear facing claw was a talon while one or all of the front facing claws were instead pounces." Good to know!
"Beauty can be considered to be neutral, sir. It is not the same as nice or good." --Nutt (pg. 194)