Webster's Revised Unabridged Dictionary · 1913

Inane

Inane , adjective

[Latin inanis.]

Without contents; empty; void of sense or intelligence; purposeless; pointless; characterless; useless.
Vague and inane instincts. — I. Taylor

Inane , noun

That which is void or empty. [Rare]
The undistinguishable inane of infinite space. — Locke