Which term best describes the deterioration of materials over time?

The term that best describes the deterioration of materials over time is "ageing." Ageing refers to the gradual decline in material properties and performance due to various factors, including environmental influences like temperature, humidity, light, and chemical exposure. This process can affect the integrity, strength, and functionality of materials, leading to potential failures or reduced effectiveness in applications.

Bearings do relate to mechanical components and their maintenance but do not pertain directly to the concept of deterioration over time in materials. Adjust refers to making changes or alterations, which does not encapsulate the natural decline process, while bend suggests a deformation or shift in shape rather than an overall deterioration of material properties. Thus, ageing is the most accurate term to describe the long-term effects on materials.