highpass

This term is a technical specification used primarily in audio engineering, electronics, and signal processing. It describes a specific functional behavior of a filter, creating a sharp contrast with lowpass filters. In professional contexts, it is often used as a compound modifier preceding the word filter, though it can stand alone as a noun in shorthand technical discussions.

When used as a noun, the term refers to the physical or digital component itself. Because it describes a specific type of electronic circuit or algorithm, it is treated as a countable entity in engineering contexts, referring to a single instance of such a filter.