1. plural of expansivity; the quality or degree of being expansive; tendency to expand or spread out.
Usage: technical/scientific context; often used in physics and materials science
2. plural of expansivity; the coefficient or measure of thermal expansion in materials.
Usage: physics/engineering term

Examples

• The expansivities of different metals vary significantly with temperature.
• Engineers must account for the expansivities of materials when designing bridges.
• The expansivities of gases are generally higher than those of solids.
• Thermal expansivities determine how much a substance will grow when heated.
• Scientists measured the expansivities of the alloy under various conditions.