The phrase "healthy baby" refers to a newborn or young child who is in good physical and mental condition, free from any serious illnesses or health issues. A healthy baby typically grows and develops normally, meets expected milestones for their age, has regular bowel movements, sleeps well, and maintains a stable body temperature. In addition to being physically healthy, a healthy baby also has good emotional and mental well-being, showing normal behavior patterns and social interactions with others. The phrase "healthy baby" is often used as a sign of joy and celebration when referring to the birth or adoption of a new child.