Definition of "defunctive"

Let the priest in surplice white/That defunctive music can/ Be the death-divining swan/ Lest the requiem lack his right.

1601, William Shakespeare, The Phoenix and the Turtle

The road was now a black tunnel floored with the impalpable defunctive glare of the sand.

1931, William Faulkner, Sanctuary, Library of America, published 1985, page 13