עֲדָשָׁה (adasha) — lentil / lens

Etymology

The word עֲדָשָׁה has accumulated at least three distinct meanings across three millennia of Hebrew usage: a legume, a freckle, and an optical element. All three derive from the same source — the shape of a lentil seed — though the paths diverged through Latin, French, and German intermediaries before converging in modern Hebrew.

In the Bible, the word appears in plural form (עֲדָשִׁים, lentils) as a food: most famously as the "red stew" (נְזִיד עֲדָשִׁים) that Esau sold his birthright to Jacob to obtain (Genesis 25:34). The phrase "mess of lentil stew" (נְזִיד עֲדָשִׁים) entered multiple world languages — including Greek — as an idiom for exchanging something of great value for a trivial immediate gain. Karl Marx invoked it in Das Kapital to describe the worker forced to sell his labor for "ein Gericht Linsen" (a plate of lentils). In the Mishnah and Talmud, the singular עֲדָשָׁה became a unit of small volume — smaller than a gris and larger than a hair's width (Mishnah Negaim 6:1) — used in measurements of ritual purity.

The Latin word for lentil, lens (genitive lentis), and its diminutive lenticula, had extended metaphorically in antiquity to refer to objects with a lentil-like shape: small bowls, indentations, and spots on the skin. The Tosefta appears to record this extension in Hebrew, using עֲדָשָׁה for a small bowl (Tosefta Shabbat 3:7). More importantly, in 11th-century France, Rashi performed a direct loan-translation from the Old French lentille (which meant both the legume and a freckle/skin spot) into Hebrew, using עֲדָשָׁה to mean freckle in his commentary on Leviticus. He even coined the elegant adjective עַדְשָׁן for a freckled person ("between freckle and freckle, the white gleams clearly"). This meaning was used through the medieval period — Abraham ibn Ezra in the 11th century proposed that applying hare's blood "removes the freckles of the face" — but was eventually displaced. In 1533, the physician Natan HaMe'ati adopted the Arabic word נֶמֶשׁ (freckle) from his medical translations, and it pushed עֲדָשֵׁי הַפָּנִים (facial lentils) out of use.

In the 16th century, the development of glass-grinding technology produced the optical lens — named lens in scientific Latin because its shape recalled a lentil. European vernacular languages followed: German Linse, French lentille, English lens. The Hebrew loan-translation was made by Mordechai Ya'avel in his 1836 science textbook Limudei HaTeva (Studies of Nature), where he refers to the eyepiece of a telescope as an "eye-lens" (Augenlinse in German), and he translates this into Hebrew using עֲדָשָׁה.

For most of the 19th and early 20th century, the plural forms for optical lenses and food lentils were identical (both עֲדָשִׁים). In 1930, the Physics Terminology Committee of the Hebrew Language Council tried to establish עֲדָשִׁים for both, but the Photography Terminology Committee overturned this a few months later, drawing a distinction that has held ever since: עֲדָשִׁים are what you eat; עֲדָשׁוֹת are what light passes through.

Key Quotes

"הַלְעִיטֵנִי נָא מִן הָאָדֹם הָאָדֹם הַזֶּה כִּי עָיֵף אָנֹכִי." — עֵשָׂו, בראשית כ"ה, ל' (requesting the lentil stew)

"כאיש עדשן שבין עדשה ועדשה מבהיק בלובן צח." — רש"י, פירוש לספר ויקרא (inventing עַדְשָׁן for "freckled man")

Timeline

• Biblical era: עֲדָשִׁים (lentils) used as food; Genesis 25:34; 2 Samuel 17:28; Ezekiel 4:9
• Mishnah: עֲדָשָׁה as a unit of small volume
• Tosefta era: עֲדָשָׁה for a small bowl (loan from Latin lenticula)
• 11th century CE: Rashi coins עֲדָשָׁה for freckle (loan-translation from Old French lentille); coins עַדְשָׁן (freckled person)
• 1533: Natan HaMe'ati introduces נֶמֶשׁ for freckle; displaces עֲדָשֵׁי פָּנִים
• 16th century: Optical lens named lens in scientific Latin
• 1836: Mordechai Ya'avel introduces עֲדָשָׁה for optical lens in Limudei HaTeva
• 1930: Hebrew Language Council Physics Committee proposes עֲדָשִׁים for both food and optics
• 1930 (months later): Photography Committee overrides: עֲדָשִׁים = food lentils; עֲדָשׁוֹת = optical lenses

Related Words

• נְזִיד עֲדָשִׁים — lentil stew; idiom for a poor exchange (Genesis 25)
• נֶמֶשׁ — freckle (Arabic loanword that displaced עֲדָשֵׁי פָּנִים)
• עַדְשָׁן — freckled person (Rashi's coinage, archaic)
• עֲדָשׁוֹת מַגְדֶּלֶת — magnifying lenses
• עֲדָשׁוֹת מַגָּע — contact lenses (modern extension)