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.
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'.
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.
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.
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 = output / input
Referring to the viscosity of a fluid, often denoted by η.
The standard Japanese term for 'viscosity'.
This liquid has low viscosity.
In physics, η is the symbol for viscosity. It is read as イータ or 粘度.
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'.
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 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.