Is it an animal? Is it a plant? Is it a mineral? Is it a thing? Is it something immaterial?

This data is immaterial to the argument.

Age is immaterial, unless you're a bottle of wine.

We are always getting away from the present moment. Our mental existences, which are immaterial and have no dimensions, are passing along the Time-Dimension with a uniform velocity from the cradle to the grave.

I knew that seclusion and solitude were very necessary for my friend in those hours of intense mental concentration during which he weighed every particle of evidence, constructed alternative theories, balanced one against the other, and made up his mind as to which points were essential and which immaterial.

An idea is an immaterial model of a real or a supposed element of reality. An idea is a fragment of our thoughts. When we think something, that single thought is an idea. Ideas are the atoms of the thoughts, and thoughts are a combination of ideas.