pyloric antrum

Pyloric antrum (antrum, lesser cul-de-sac) is the initial portion of the pyloric part of the stomach. It is near the bottom of the stomach on the left side of the pyloric sphincter, which separates the stomach and the duodenum. It may temporarily become partially or completely shut off from the remainder of the stomach during digestion by peristaltic contraction of the prepyloric sphincter; it is demarcated, sometimes, from the second part of the pyloric part of the stomach (pyloric canal) by a slight groove.
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Pyloric antrum n. The bulging part of the lower end of the stomach between the body of the stomach and the pyloric canal. [more]Pyloric antrum - Community and Resources

noun
any cavity inside the body, especially one in bone
mastoid antrum = cavity linking the air cells of the mastoid process with the middle ear
maxillary antrum or antrum of Highmore = one of two sinuses behind the cheekbones in the upper jaw
pyloric antrum = space at the bottom of the stomach, before the pyloric sphincter