* Intangible: This is the most common and direct opposite, referring to something that cannot be touched or physically perceived.
* Abstract: This refers to something that is theoretical or conceptual, rather than concrete.
* Ethereal: This describes something that is delicate, light, and otherworldly.
* Impalpable: This means something that cannot be felt or touched.
* Incorporeal: This refers to something that lacks a physical body.
Examples:
* Tangible: A physical book
* Intangible: Happiness
* Abstract: The concept of freedom
* Ethereal: A dream
* Impalpable: Smoke
* Incorporeal: A ghost
The best opposite for "tangible" will depend on the specific situation and the meaning you want to convey.