ETB

ETB is an acronym with several meanings across different fields, and its exact meaning depends on context.

In travel and aviation, ETB commonly stands for Estimated Time of Boarding, indicating when boarding is expected to begin. It is often presented alongside ETA (Estimated Time of Arrival) and ETD (Estimated Time of Departure), but usage can vary by airline or airport. Passengers should rely on official announcements for current boarding information.

In technology and engineering, ETB denotes Embedded Trace Buffer, a memory region used to capture instruction traces for debugging and development of microprocessors, notably in ARM CoreSight architectures. ETBs enable developers to store trace data for later retrieval by debugging tools.

In biology and medicine, ETB refers to the endothelin receptor type B, a G-protein coupled receptor activated by endothelins. It participates in vascular tone regulation and neuroendocrine signaling, with roles in conditions such as pulmonary arterial hypertension and certain neurological processes.

Other uses exist in finance and other sectors, but ETB does not have a single universally accepted meaning outside specific domains; meanings are driven by context and may include industry-specific terms or organization names. It is distinct from similar abbreviations like ETA or ETD and can cause confusion if not clarified.