Translation guide
The Greek letter η (eta). This guide covers how to refer to the letter itself in Japanese, as well as its use in scientific and mathematical contexts.
イータ
What is the Japanese name for the Greek letter η?
Referring to the letter itself, such as when spelling or naming it.
The standard Japanese name for the Greek letter η, borrowed from English 'eta'.
この記号はイータです。
This symbol is eta.
In written contexts, the Greek letter itself is often used directly, especially in mathematics and science. It is read as イータ.
ηはギリシャ文字の一つです。
Eta is one of the Greek letters.
Expressing the concept of efficiency, often represented by the Greek letter η.
The standard Japanese word for 'efficiency'. Used in engineering, physics, and everyday contexts.
このエンジンの効率は高い。
This engine has high efficiency.
In technical writing, the symbol η is used to denote efficiency. It is read as イータ or simply referred to as 効率.
η = 出力 / 入力
η = output / input
Referring to the viscosity of a fluid, often denoted by η.
The standard Japanese term for 'viscosity'.
この液体の粘度は低い。
This liquid has low viscosity.
In physics, η is the symbol for viscosity. It is read as イータ or 粘度.
ηは流体の粘度を表す。
η represents the viscosity of a fluid.
Referring to the refractive index of a material, sometimes denoted by η.
The standard Japanese term for 'refractive index'.
水の屈折率は約1.33です。
The refractive index of water is about 1.33.
In some contexts, η is used for refractive index. More commonly, n is used, but η may appear.
ηは屈折率を示すことがある。
η sometimes indicates the refractive index.
In technical Japanese documents, Greek letters are commonly used as symbols and are read using their Japanese names (e.g., イータ for η). When speaking, you can say the name or the concept it represents depending on context.