What term describes someone who is abrupt and curt in manner or speech?

The term that best describes someone who is abrupt and curt in manner or speech is "brusque." This adjective specifically conveys a sense of bluntness combined with a lack of politeness, suggesting a sharp and direct way of communicating that may come off as ungracious or dismissive. Using "brusque" highlights the specific quality of being not only direct but also potentially discourteous, setting it apart from other terms.

While other terms like "rude" and "surly" also imply a negative demeanor, "rude" is a broader term that encompasses various behaviors beyond just speech, and "surly" more specifically connotes a bad-tempered disposition. The word "blunt" can refer to being straightforward and frank, but it does not inherently carry the negative connotation of abruptness or a curt manner in communication. Therefore, "brusque" is the most accurate term to convey the intended meaning in the context of being abruptly curt in speech or manner.