"Material change" refers to a significant or important alteration or modification that has a noticeable impact. It implies a change that is substantial or considerable in nature and can have a notable effect on a situation or outcome.
Other material change in circumstances may include a change in the child's needs, a change in a parent's schedule or a change in a parent's treatment of the child. (divorcesource.com)
Often when parties separate, they include a clause in their separation agreement that says spousal support can end or be reviewed when there is a «material change of circumstances». (oakvillemediation.com)
Scientists want to study how materials change state and lose energy. (sciencedaily.com)