What does it mean to "rarefy" something?

To "rarefy" something means to make it thinner or less dense. This term is often used in scientific and technical contexts, especially concerning gases or materials. For instance, when one talks about rarefying air, it refers to reducing the air pressure or density, which can occur at higher altitudes. The concept conveys an action of dilution or lightening, effectively leading to a state of increased subtlety or emptiness.

In contrast, filling something completely would imply the opposite action of making it denser or more substantial, while bringing about something abruptly suggests a sudden change rather than a gradual thinning. Causing something to slow down involves issues of velocity and performance rather than altering its density. Thus, the meaning of "rarefy" aligns directly with making something less dense, making the choice to describe this action as such correct and appropriate.