Read this and answer the question. If the question is unanswerable, say "unanswerable".

Some scientific materialists have been criticized, for example by Noam Chomsky, for failing to provide clear definitions for what constitutes matter, leaving the term "materialism" without any definite meaning. Chomsky also states that since the concept of matter may be affected by new scientific discoveries, as has happened in the past, scientific materialists are being dogmatic in assuming the opposite.

How does Chomsky define materialism?
unanswerable