An orphan (from the Greek ορφανός) is a person (or animal), who has lost one or both parents, often through death. One legal definition used in the USA is someone bereft through "death or disappearance of, abandonment or desertion by, or separation or loss from, of both parents" *. Common usage limits the term to children, (or the young of animals) who have lost both parents. On this basis half-orphans are those with one surviving parent.
In certain animal species where the father typically abandons the mother and child at or prior to birth, the child will be called an orphan when the mother dies regardless of the condition of the father.
In past times and in much of the third world, orphans often lived homeless as "street urchins", or were cared for in almshouses, orphanages, or occasionally monasteries; most modern people feel that this was a mistake, or, at the least, provided suboptimal care. In particular, almshouses were often shared with the adult homeless and the (sometimes dangerously) mentally ill in an age when many mental illnesses were untreated.
In some nations faced with war and AIDS, a significant proportion of the young population is orphaned, which is a major humanitarian crisis. In the People's Republic of China, infant daughters are sometimes abandoned due to the one child policy, which also creates a significant number of effective orphans.
Orphans typically suffer from adjustment problems related to identity, according to studies.
Prior to the establishment of state care for orphans in First World countries, many charities such as Dr Barnardo's Homes (now simply Barnardo's) existed to take care of destitute orphans.
Many orphans are also foundlings, and many foundlings are effective orphans, and their search may include attempts to find their parents, or other relatives. Even if the parents are dead, the foundling orphan, like Oliver Twist, may learn who they were.