Can Altering Be an Adjective?

Altered is an adjective that describes anything that's been changed or modified. You might need altered clothing after you succeed at your diet, or feel like you are in an "altered state" after you've been hypnotized. Altered behavior is behavior you have changed, like the altered habits of your housebroken dog.

What is the adjective form of alter?

alterated. (obsolete or nonstandard) altered; changed.

Can Alter be a noun?

The act of altering or making different. The state of being altered; a change made in the form or nature of a thing; changed condition.