Though not the most common occurrence, Automation Engineers sometimes become Automation Engineering Managers, where the average income is $105K per year.
For example, the antrum of the stomach (gastric antrum) is a portion before the outlet, which is lined by mucosa and does not produce acid. The paranasal sinuses can be referred to as the frontal antrum, ethmoid antrum, and maxillary antrum.
Definition of Antrum. 1. n. A cavern or cavity, esp. an anatomical cavity or sinus. Definition of Antrum. 1. Noun. (biology) A bodily cavity, especially one having bony walls, especially one in the sinuses.