Medical Definition of Human immunodeficiency virus. Human immunodeficiency virus: HIV, the cause of AIDS. HIV has also previously been called the human lymphotropic virus type III, the lymphadenopathy-associated virus and the lymphadenopathy virus. No matter what name is applied, it is a retrovirus. (A retrovirus has an RNA genome and a reverse transcriptase enzyme.
Definition of custody for English Language Learners. 1  law : the legal right to take care of a child (such as a child whose parents are divorced) : 2  the state of being kept in a prison or jail. : 3  the act of protecting or taking care of something.
Custody Definition: Related Terms: Guardianship, Access, Bird's Nest Custody, Physical Care, Child, Legal Custody, Joint Custody. Custody can be in relation to family law, property or in regards to a prisoner.