Inane

Part of speech: noun (n.)

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

Part of speech: adjective (a.)

Without contents; empty; void of sense or intelligence; purposeless; pointless; characterless; useless. "Vague and inane instincts." I. Taylor. -- In*ane"ly, adv.