The confusable quintet: Names of the 5 fingers and their origins

There is a Persian proverb, "All fingers are not the same," an expression about variations. All of our five fingers in one hand come in different sizes, shapes, orientations and names – along with their own unique history. 

They showcase a surprising depth of cultural variation and similarity as well.

Fingers are a glaring exception among our limbs, most of which either come alone or in pairs. Against one nose and one tongue, we sport two eyes, two knees, two feet. But there is a glaring exception when it comes to fingers – a party of five on each hand.  

The condition of having five fingers, pentadactyly, is pervasive in the biological world. The five fingers are vexingly similar – they differ slightly in size and dexterity, but all have that pucker-knuckled, nail-capped look. 

One may wonder how have people, in different times and places, solved the problem of identifying which finger they slammed in the door. That how have they named the members of this confusable quintet; answer to that question requires a tour of the inventiveness of the human mind.

First and fattest of the bunch
Appearance is an especially common source of thumb names. The modern English word, for example, comes from an older word meaning "stout" or "thick." Other languages highlight the fact that the thumb is powerful, despite its short stature. 

The Latin term for this member – pollex, still used in medical contexts – comes from a verb meaning "to be strong." In Kurdish, these associations of compactness and strength come together in the label "ram finger."

A broader pattern is hinted in the case of "ram finger". Often the fingers are seen as animate beings, little agents with their own personalities. People thus, at times name them after animals or after human social roles. 

In some Native American languages, the thumb is called the "chief finger." Elsewhere it is cast as a family member – the terms "mother," "father," "older brother," or "grandfather finger" are all attested. 

In Greek, it is known as "what is opposite the fingers." In several Turkic languages, it is known as the "head finger." In some parts of the Middle East and the Mediterranean, the name for the thumb stems from an unsavory function that, thankfully, it no longer has to serve (much): the lice killer.

Pointing, shooting and cursing 
The finger's use in pointing earns it the label. The English word index is rooted in an earlier word meaning "to show." Names that associate this finger with pointing can be found around the globe.

It is called the forefinger by English speakers because of its position as the first of the fingers proper, excluding the thumb. Texts from the Medieval times refer to it as the "greeter" and "teacher." 

For reasons unknown, in Anglo-Saxon times, it was known as the "scythe finger"; and as the "shooting finger," because it was used to draw back a bowstring. It is considered the finger of beckoning, cursing, and protecting in Iranian languages.

Because of its use in the Muslim practice of "Shahada" or profession of faith, it is also known as the "prayer finger" or "testimony finger" in modern Turkish. One of its most colorful nicknames was based on its penchant for swiping up sauces: the "pot licker."

Long and lewd
In English language, the middle finger gets the name for its central position – the "half-way finger" as it is otherwise known as. The idea is embellished in Native American Choctaw people, where it is known as the "middle son." 

In some Turkic languages, it is dubbed the "middle poplar," evoking the image of the fingers as a stand of trees. Its length is another salient aspect of this finger; hence monikers like the "long finger" or "tall finger," and colourful variants like the "high grass" or "tall Turk."

The middlemost finger was known as the digitus impudicus or obscenus in Latin, that is, the shameless or lewd finger. It is suggested that these terms were due to its use in one of the crudest gestures by people, but a deeper reason may lie in its appearance. 

When extended and flanked on either side, the finger in the middle is said to resemble a penis and testicles. The crude gesture is motivated by this phallic form. Another explanation for the lewdness, as one observer notes, is that this is the digit often used to stimulate the female genitals.

Fourth in line
Origins of the "ring finger" nickname is easily understood from modern ring-wearing practices. According to medieval belief, a nerve or artery ran from the ring finger to the heart. This notion led people to don rings on this digit. It also gave the finger a prominent role in medical lore and practice. For example, doctors would use the ring finger when applying treatments; this inspired the terms "doctor finger," "healing finger," "heart finger," and "leech finger" – the last because leech was another word for physician.

A somewhat paradoxical name for the finger is also popular – the "nameless finger", a label once used in parts of Europe. This lead German author Wilhelm Grimm, famous for his fairy tales, to speculate about the origins of that moniker. 

One of his ideas was that the name alludes to this digit's squeaky-clean reputation, in contrast to that of its lewd neighbor. The finger's quasi-mystical uses in healing is another reason that some dared not speak its name.

The similar paradoxical label is found in Native American languages and in Chinese culture. It unlikely that it stems from cultural beliefs peculiar to Europe. Rather, the nameless-ness of this finger may be due to its utter "unremarkability." Sandwiched between more distinctive fingers, and not particularly useful, the ring finger is the forgettable of the bunch.

Littlest and the last
The pinky is the loveable runt of the hand. Other than mein, the English word has nothing to do with the colour pink – rather, it was borrowed from Dutch. The deeper origins of the word are debated, but it may have stuck around because it bears a suffix ("-y") often used in English for small, endearing things. 

Fixation on the size of this digit is found all over the world. It is variously called the "baby," "youngest child," or "last-born daughter." In Turkish, it is known as the "sparrow finger," after the distinctively diminutive bird. A related idea is that this finger is a bit of a straggler. In some places, it is known as the "orphan" or "behind" finger.

Terms based on its functions are somewhat scarce, since the finger does not have a very active function in our quotidian activities. However, one exception is found in Latin, where the pinky was labeled the auricularis – "ear finger". In modern French this aural association can be found; due to what is perhaps this finger's most noteworthy talent: wax removal from the ear.

Finger-naming problems and their solutions showcase the human mind at work and at play. In language after language, digits are named for their appearance, position, and size. They are likened to birds, dogs, and sheep, compared to chiefs, children, parents, and grandparents. 

They are recognized for their roles in praying, hunting, healing, cursing, licking pots, and squashing pests. From this colourful compendium, at one hand, unexpected patterns are found and on the other, delightful diversity.