"The Last Incantation" by Clark Ashton Smith

Susran: I can come up with a lot of possible pronunciations of this, but sadly, we have no hint from the author what he had in mind.

perdurable: enduring; imperishable

prelate: a bishop or other high ecclesiastical dignitary

fulvous: reddish or brownish yellow; tawny

crotali: A Turkish musical instrument, like the ancient cimbalom

meet, as in "is it meet": suitable. It appears to have had this usage until some time in the first half of the 20th century. I've certainly never heard it used this way until now. Weird.

coign: a projecting corner or angle of a wall or building

thurible: a censer. What's a censer? An incense burner. In the European sense, which is presumable here, typically made of metal, often gold or silver, typically used in religious ceremonies. An image search will make it instantly obvious if you still don't recognize what this is.

Lethe: In Greek mythology, one of the rivers of Hades, known as the River of Forgetfulness, as those who drank from it experienced complete memory loss.

innominable: incapable of being named

exigent: pressing; demanding

evanescent: soon passing out of sight, memory, or existence; quickly fading or disappearing

immedicable: unable to be healed or treated

To follow along: http://www.eldritchdark.com/writings/short-stories/112/the-last-incantation