Lying-in is a phrase that is often associated with childbirth, referring to the period of time a mother spends recovering after giving birth. However, there are several synonyms for lying-in that can be used to expanded its meaning. Some of these synonyms include postnatal recovery, confinement, maternity stay, childbirth rest, and puerperium. Postnatal recovery is commonly used to refer to the time a mother spends recovering from childbirth, while confinement is often associated with historical practices that required mothers to rest for an extended period after giving birth. Maternity stay refers to time spent in a hospital or birth center after giving birth, and childbirth rest and puerperium are medical terms used to define the period of rest following childbirth.