Ana or ANA may refer to:
Anal sex or anal intercourse is generally the insertion and thrusting of the erect penis into a person's anus, or anus and rectum, for sexual pleasure.
Anarchism is a political philosophy that advocates self-governed societies based on voluntary institutions.
Anatomy is the branch of biology concerned with the study of the structure of organisms and their parts.
An analgesic or painkiller is any member of the group of drugs used to achieve analgesia, relief from pain.
Anarcho-capitalism is a political philosophy that advocates the elimination of the state in favor of individual sovereignty, private property, and free markets.
Standard anatomical terms of location deal unambiguously with the anatomy of animals, including humans.
In electronics, an analog-to-digital converter (ADC, A/D, A–D, or A-to-D) is a system that converts an analog signal, such as a sound picked up by a microphone or light entering a digital camera, into a digital signal.
Anatolia (from Greek Ἀνατολή, Anatolḗ – "east" or "(sun)rise"; in modern Turkish: Anadolu), in geography known as Asia Minor (from Greek: Μικρὰ Ἀσία Mīkrá Asía – "small Asia"; in modern Turkish: Küçük Asya), Asian Turkey, Anatolian peninsula, or Anatolian plateau, is the westernmost protrusion of Asia, which makes up the majority of modern-day Turkey.
Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death. It typically causes more than one of the following: an itchy rash, throat or tongue swelling, shortness of breath, vomiting, lightheadedness, and low blood pressure.