Learn English – Word to describe object that can be physically passed through

single-word-requests

I'm looking for a word to describe something that can be physically passed through like a ghost, mist, or a gas. Initially, I was thinking of the work transparent, but I feel like this is better used to describe something that is see through.

Best Answer

Borrowing from Carl Sagan's The Dragon in My Garage, which suggests this word for specters:

incorporeal - having no physical body or form

(Definition from Merriam-Webster.)

I have to take issue with permeable. A sieve is permeable, a sponge is permeable, but unless you're a molecule or a virus or something similarly small you can't pass through.