What Does the Word Fidelity Mean?
The word "fidelity" has come to have several different meanings that can be applied in several different contexts. The most common meanings for "fidelity" are rooted in the word's Latin origins.
Latin Meaning
"Fidelity" is derived from the Latin word "fidelis," which means faithful or loyal. Many well-known sayings have developed from this Latin root, the most famous likely being the United States Marine Corps' motto "semper fidelis," which means "always faithful."
Feudal Loyalty
The word "fidelity" was first used to describe the duty one had to a lord or king. This meaning of the word is also loosely connected to the term "fealty," which is essentially a pledge of allegiance.
Monogamy
When referencing romantic relationships, "fidelity" has come to mean sexual monogamy, especially in Western cultures. Marriage vows are often called promises of fidelity, and those who commit adultery are said to be with "little fidelity." The most famous examples of this can be seen in Shakespeare's plays, particularly in "All's Well That Ends Well," when Helena is accused by Bertram of having "little fidelity."
Music and Electronics
In the mid-20th century, "fidelity" came to refer to the comparison between an original music recording and a copy made from it. The term "hi-fidelity" audio came from this usage of the word, and this term eventually got shortened to "hi-fi"
In the field of electronics, fidelity refers to input and output signals, rather than the quality of sound.
Simulation and Models
The science and technology field attached a technical meaning to "fidelity" by using it to refer to a measurement of realism. The degree to which a simulation or model reproduces a real-life feature, object or condition can be called fidelity in the scientific context. The fidelity of simulation has been referred to as "degree of similarity."
