The clinical term for blood in the vomit that appears as "coffee grounds" is known as:

The clinical term for blood in vomit that resembles "coffee grounds" is indeed referred to as coffee grounds emesis. This term is used to describe the appearance of partially digested blood that results from bleeding in the upper gastrointestinal tract, such as the stomach or the esophagus.

When blood is present in the stomach, it is subject to the digestive process, which causes it to change in appearance. The brownish, granular texture resembles coffee grounds due to the action of gastric acid breaking down the hemoglobin in the blood. This visual characteristic is significant in clinical assessments, as it helps healthcare providers determine the source of bleeding and its potential severity.

In contrast, hematochezia typically refers to the passage of fresh red blood from the rectum and is associated with lower gastrointestinal bleeding. Melena, on the other hand, indicates the presence of digested blood, but typically refers to dark, tarry stools rather than vomit. Thus, coffee grounds emesis specifically aligns with the description provided in the question, making it the accurate terminology to use in this clinical context.