coup d'Ã©tat. a sudden and decisive action in politics, especially one resulting in a change of government illegally or by force. Origin of coup d'Ã©tat.
The human immunodeficiency virus (HIV) is a lentivirus (a subgroup of retrovirus) that causes HIV infection and acquired immunodeficiency syndrome (AIDS).AIDS is a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive.he human immunodeficiency virus (HIV) is a lentivirus (a subgroup of retrovirus) that causes HIV infection and acquired immunodeficiency syndrome (AIDS).
Definitions: 1  HIV-Human Immunodeficiency Virus, the virus that causes AIDS. 2  AIDS-Acquired Immunodeficiency Syndrome, the condition that results from HIV infection. 3  AIDS is distinguished from HIV by the presence of an opportunistic infection or a T-cell count of 200 or less. AIDS-Acquired Immunodeficiency Syndrome, the condition that results from HIV infection. 2  AIDS is distinguished from HIV by the presence of an opportunistic infection or a T-cell count of 200 or less.