The phrase "in childbed" is an old-fashioned term that refers to the period of time immediately following a woman's delivery of a baby. There are several synonyms that can be used in place of "in childbed," such as "postpartum," which is commonly used in modern medical contexts. Other alternatives include "after birth," "in confinement," and "in the lying-in period." Each of these phrases emphasizes that the mother is resting and recovering from the process of childbirth. It's important to note that the terminology used may vary depending on cultural and historical context, so it's always best to clarify any potential confusion with specific language and details.