Meaning of "wane" in "wane, willing flesh"

In his novel The Long Walk, Stephen King writes:

How must it have been, dry-humping that wane, willing flesh?

It seems to me that "wane" is being used as an adjective in this instance, however I haven't been able to find any Dictionary entries with senses of "wane" under an Adjective heading.

Is King using "wane" here as an adjective, and if so, or if not, what would it mean in this instance?

Solution 1:

Well, the OED has "wane" as an adjective considers it obsolete. Meanings are described as:

1. Lacking, absent, deficient
2. Destitute of.
3. [...]
4. Incomplete; not fully formed, or properly shaped. Of the moon: Not full [this might be to closest to familiar usage today, as in the verb "to wane"]
5. Insufficient, (too) small.

When consulting google n-gram, we find that today wane as a verb is about 50 times as common as is wane as an adjective:

I am guessing your author is considering the flesh in question to be deficient, too easy and altogether not worthy.