What term indicates something that is usual or customary?

The term that indicates something that is usual or customary is "habitual." This word is derived from "habit," which refers to a repeated behavior or practice that individuals engage in regularly. When something is described as habitual, it suggests that it occurs in a consistent or standard manner due to its established nature in one’s routine or culture. This aligns directly with the notion of being customary or typical in behavior.

The other terms do not fit this definition. "Paramount" refers to something that is of the highest importance or significance, rather than what is regular or customary. "Appropriate" means suitable or fitting for a particular purpose or situation, which does not necessarily relate to the concept of being usual. "Exacerbation" refers to an increase in the severity of a situation or condition, often used in medical contexts, and does not convey the idea of regularity or customary practice. Therefore, the focus on the repetitiveness and standard nature of behaviors makes "habitual" the correct choice for something that is usual or customary.