What is defined as an interjection that lends emphasis and sometimes serves as a profanity?

The term that is defined as an interjection lending emphasis and sometimes serving as a profanity is an expletive. Expletives are often used to express strong emotions, add emphasis to a statement, or even serve as filler in sentences. They can be mild or profane, depending on the context and the speaker's intention.

In various forms of communication, expletives can intensify the sentiment being conveyed or capture the listener's attention. Their usage is prevalent in both written and spoken language, allowing for emotional expression that resonates with an audience. The other options do not align with this definition; for example, a euphemism refers to a mild or indirect word used to substitute for one considered too harsh, while a fable is a narrative that imparts a moral lesson, and an exclamatory is a type of sentence that expresses strong emotion but does not specifically denote profanity or emphasis in the same way as an expletive.