A polymer is a substance composed of macromolecules.

The receiver will contain pipes holding a eutectic salt-like substance composed of lithium fluoride-calcium difluoride.

Chemical elements are substances composed of only one type of atom and they cannot be broken down further.

The lights passed through the suit via Light Tape, a substance composed of Honeywell lamination and Sylvania phosphors.

Primarily used in chemistry or mining, polymetal or polymetallic refers to a substance composed of a combination of different metals.

For starters, an alloy is a substance composed of two or more metals.

Heterogeneity in the sciences is a substance composed of dissimilar or diverse parts.

A compound is a pure substance composed of two or more elements combined in fixed and definite proportions.

Shoe polish consists of a waxy colloidal emulsion, a substance composed of a number of partially immiscible liquids and solids mixed together.

For example,a single polymeric molecule is appropriately described as a "macromolecule" or "polymer molecule" rather than a "polymer", which suggests a substance composed of macromolecules.