The process whose specific outcome is the progression of the placenta over time, from its formation to the mature structure. The placenta is an organ of metabolic interchange between fetus and mother, partly of embryonic origin and partly of maternal origin. [ https://www.worldcat.org/search?q=bn%3A068340007X GOC:add ]

Synonyms: placental development placentation

This is just here as a test because I lose it