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.
2. gestation-the state of being pregnant; the period from conception to birth when a woman carries a developing fetus in her uterus. maternity, pregnancy. fetal movement, foetal movement-motion of a fetus within the uterus (usually detected by the 16th week of pregnancy).estation. n. 1. (Zoology). a. the development of the embryo of a viviparous mammal, between conception and birth: about 266 days in humans, 624 days in elephants, and 63 days in cats. b. (as modifier): gestation period.