What is the action of laughing loudly and in an unrestrained way called?

The action of laughing loudly and in an unrestrained way is best described by the term "cachinnate." This word specifically refers to the act of laughing in a loud, uncontainable manner, often associated with sheer joy or amusement. It captures the essence of a robust, hearty laugh that is both boisterous and uninhibited, conveying a vivid sense of delight or mirth.

While other choices describe different types of laughter, they do not fully encompass the specific quality of loudness and unrestrained nature associated with cachinnating. For instance, "guffaw" denotes a loud, hearty laugh but can sometimes imply a less refined, more abrupt quality. "Chortle" suggests a laugh that is somewhat suppressed, often mingled with snorts, whereas "giggle" signifies a light, silly laugh that is typically quieter and more restrained. Thus, cachinnate stands out as the term that precisely defines the action of laughing loudly and without restraint.