There are numerous synonyms for the phrase "brick in" that can be used to describe the act of enclosing or sealing off an area. Some common alternatives may include to wall up, to barricade, to block off, to close off, to isolate or to segregate. Each of these synonyms highlights the idea of creating a physical barrier or boundary either to restrict access or protect from harm. Additionally, these terms can also be used more metaphorically to describe emotionally isolating oneself or restricting communication channels. Choosing the right synonym for "brick in" depends on the context of use and the desired tone or emphasis.