Fricatives are a group of consonant sounds that are produced by forcing air through a narrow space in the mouth, resulting in a hissing or buzzing sound. There are several synonyms for the term "fricatives." One commonly used term is "spirants," which refers to sounds produced by forcing air through a narrow channel in the mouth without completely closing it off. Another synonym for fricatives is "stridents." This term specifically refers to fricatives that are produced by causing the air to be constricted, leading to a high-pitched, hissing sound. Other synonyms include "surds," which are non-voiced fricatives, and "continuants," which are sounds that can be prolonged without interruption.