When it comes to synonyms for the phrase "be gravid," there are many options. You could say that someone is "expecting," "carrying a child," "with child," or "pregnant." Other alternatives include "in the family way," "in a delicate condition," or "up the duff." Depending on the context and tone of the conversation, some phrases may be more appropriate than others. However, all of these synonyms are common and widely understood by English speakers. It's important to choose the right phrase depending on the situation, but with so many alternatives, it's easy to find a suitable way to describe someone who's pregnant.