The Acquired immune deficiency syndrome (AIDS) refers to the disease caused by the human immunodeficiency (or immune deficiency)  virus (HIV) that attacks the immune system and leaves the person susceptible to unusual infections.

AIDS is a viral disease that can be transmitted from a mother to her fetus or neonate and that results in a weakening of the body.

Other definition:

Acquired immune deficiency syndrome (AIDS) refers to the progressive impairment of the immune system by the human immunodeficiency virus (HIV). A diagnosis of AIDS is made on the basis of the presence of one or more specific opportunistic infections.

Other definition:

Acquired Immune Deficiency Syndrome  refers to a immune deficiency caused by viral infection and resulting in vulnerability to a wide range of bacterial, viral, and malignant diseases.

Other definition:

The Acquired Immune Deficiency Syndrome  refers to a condition of increased susceptibility to opportunistic diseases which resulted from an infection with HIV, which destroys the body’s immune system.

Other definition:
AIDS or Acquired immune deficiency syndrome is a disorder in which the immune system is gradually weakened and eventually disabled by the human immunodeficiency virus (HIV). It is a condition of increased susceptibility to opportunistic diseases; results from an infection with HIV, which destroys the body’s immune system; an immune deficiency caused by viral infection and resulting in vulnerability to a wide range of bacterial, viral, and malignant diseases caused by HIV