Illusory

adjective/ɪˈlu.sə.ɹi/philosophy

Definition

Based on illusion; not real.

Etymology

Borrowed from Middle French illusorie (modern French illusoire), derived from Latin illūsōrius (“mocking, ironical”).

Synonyms

unreal, illusive

In a sentence

The cost savings turned out to be illusory once you factored in migration effort.