Achromatic means “colorless”, and the etymology comes from a (no) and khroma (color). Synonym is colorless.
Achromatic is used in the field of optics. For example, an achromatic lens is a lens used to correct color blur. Achromatic vision (All-color blindness) is an unusual disease that makes color unrecognizable.
Amnesia means “memory loss”, and the etymology comes from a (no) and mnasthai (remember). Synonym is memory loss.
There are two types of memory: declarative memory and procedural memory. Amnesia means a disorder of declarative memory in memory loss. When you get amnesia, you forget your name, family, company you worked for.
Amnesty means “reduction of punishment”, and the etymology comes from a (no) and mnestis (memorable). The synonym is pardon.
Amnesty is to lighten punishment for criminals without judicial proceedings. In Japan the Cabinet will decide, the Emperor will approve. When the Emperor is born, married, and pass away, the government celebrates it and give an amnesty to the criminals.
Amnesty is also used for famous organization name. Amnesty International is a large non-governmental organization appealing for abolition of the death penalty, protection of human rights, relief of refugees.
Anemia means “lack of red blood cells”, and the etymology comes from an (no) and haima (blood).
Anemia means that there are few red blood cells or hemoglobin in the blood. Hemoglobin in erythrocytes has a role to carry oxygen to the whole body. When red blood cells become few, the amount of oxygen in the body decreases, and palpitations and shortness of breath are likely to occur.
The main cause of anemia is lack of iron or bleeding. You should take nutrition properly with your daily diet to avoid anemia.
Anesthesia means “medical operation to stop you feeling pain”, and the etymology comes from an (no) and aisthesis (sensation).
Anesthesia is a procedure that artificially suppresses pain by medication. Patients can withstand the pain of surgery by receiving anesthesia.
There are two types of anesthesia, local anesthesia and general anesthesia. Local anesthesia is anesthesia which partially eliminates pain without losing patient’s consciousness. It is used in ophthalmology, otolaryngology, urology and dental surgery.
General anesthesia is anesthesia that makes the whole body painless and makes the patient unconscious. It is used for typical laparotomy surgery.
Anonymous means “unknown by name”, and the origin is derived from an (no) and onyma (name). Its synonym is nameless.
Criminals send an anonymous letter to intimidate the target. The press organizations in Sweden and South Korea are conducting anonymous reports.
By doing anonymous reports, we can protect the privacy of the suspects, victims and persons concerned. The disadvantage of anonymous coverage is that there is no guarantee of truth and that criminals receive no social punishment. The antonym is real name report.
Democratic countries adopt anonymous voting. The whistleblower responds to the interview on condition of anonymity. Anonymous is also used for organization name. Anonymous of hacker group makes political claim by using DDoS attack and hacking.
Apathy means “lethargy”, and the etymology comes from a (no) and pathos (emotion). Synonyms are languor, lethargy.
Apathy is a state in which feelings become indifferent to what is usually moved. It is considered to be the main symptom of depression.
Student apathy is a lethargic state peculiar to university students. Male students, who are serious and mentally weak, are likely to have this illness.
Apathy is also used in the field of politics. Recently, political apathy has spread among young people. It leads to a decline in the voting rate in the election.
Aphasia means “difficulty of speaking, writing and reading”, and the etymology comes from a (no) and phasis (pronunciation).
Aphasia is a state in which language function has been impaired due to damage of the brain’s language center. Aphasia is a type of high-order brain dysfunction that is the same as memory impairment, attention disorder, paralysis, etc.
When aphasia develops, words that you want to say do not come up and you can not understand the letters. The main cause of aphasia is brain damage due to stroke or accident.
Aphonia means “medical condition that you cannot make voices”, and the etymology comes from a (no) and phone (sound). The original meaning is aphonia (a state where words do not come out) in Greek.
Aphonia is a condition in which, due to stress or trauma, voice can not be output despite the absence of abnormality in the throat. Aphonia is a psychogenic disorder.
To treat aphonia, let’s see a psychiatry department or psychosomatic medicine department.
apoliticalは「政治的無関心」を意味し、語源はa（無い）とpolitical（政治）に由来します。同義語はindifferent to politicsです。
Apolitical means “politically indifference”, and the etymology comes from a (nothing) and political (politics). Synonyms are indifferent to politics.
Recently there are an increasing number of young people who become apolitical, which has led to a decline in the voting rate of the elections.
Atheism means “the idea that there is no God anywhere”, and the etymology comes from a (no) and theos (god).
Atheism is a way of thinking that God does not exist in the world. Because atheism is a confrontational relationship with existing religion, atheists are disliked in a religious area. Some atheists assert that they are agnostic to avoid useless conflict.
In Islamic values, atheism is considered evil. In some Muslim countries, writing atheism in the religious section of the document may result in disadvantageous treatment.
atom /ˈæṭəm/ ：原子
Atom means “the smallest part of element”, and the etymology comes from a (no) and tomos (cut). The original meaning is atomus (particle which can not be divided) in Latin.
An atom is a minimum unit of an element. Atom is composed of nuclei and electrons. For example, hydrogen molecules, forming hydrogen gas, are composed of two hydrogen atoms. Oxygen molecules, forming oxygen, are composed of two oxygen atoms.
Likewise, water is made up of water molecules, and water molecules are composed of two hydrogen atoms and one oxygen atom.