nugatory

vain, nugatory, otiose, idle, empty, hollow mean being without worth or significance. vain implies either absolute or relative absence of value.

• • vain promises

nugatory suggests triviality or insignificance.

• • a monarch with nugatory powers

otiose suggests that something serves no purpose and is either an encumbrance or a superfluity.

• • a film without a single otiose scene

idle suggests being incapable of worthwhile use or effect.

• • idle speculations

empty and hollow suggest a deceiving lack of real substance or soundness or genuineness.

• • an empty attempt at reconciliation
• • a hollow victory