impalpable
/ˌɪmpɑːlˈpæbəl/Definitions
1. adjective
Impossible to touch or feel because it is too fine, thin, or intangible.
“The politician’s promises were often described as impalpable, lacking any real substance.”
2. noun
Something that is impossible to touch or feel.
“The concept of happiness can be an impalpable idea that’s hard to grasp.”