I was first told that my aorta is slightly dilated at 4.0 cm. There is some variation in the way the term aneurysm is used. For the thoracic aorta, most agree that at a diameter of 4.0 cm it has reached a size that is considered an aneurysm. The word dilated refers to the enlargement of the aorta.
Called also neonate and newborn. premature infant (preterm infant) one born before a gestational age of 37 completed weeks (259 days). The duration of gestation is measured from the first day of the last menstrual period and is expressed in completed days or weeks.
An infant (from the Latin word infans, meaning unable to speak or speechless) is the more formal or specialised synonym for baby, the very young offspring of a human or other animal. A newborn is, in colloquial use, an infant who is only hours, days, or up to a few weeks old. In medical contexts, newborn or neonate (from Latin, neonatus, newborn) refers to an infant in the first 28 days after birth; the term applies to premature, full term, and postmature infants; before birth, the term fetus is used.