What it means
مکعب (moka’ab) is a borrowing from Arabic, built on the root ک-ع-ب (k-ʿ-b), which originally referred to the ankle bone, a roughly cube-like knob. From that root, Arabic mathematicians developed the geometric term for a cube, and Persian borrowed it wholesale. Today مکعب works as a noun (a cube, a cube-shaped object) and as an adjective in compounds: متر مکعب (metr-e moka’ab) means cubic metre, سانتیمتر مکعب means cubic centimetre. A close related word is مکعب مستطیل, a rectangular box, which is literally a rectangular cube.
How to use it
- قند مکعبی میخوری؟ (qand-e moka’abi mikhori?) “Do you want a sugar cube?”
- ریشه مکعب عدد هشت دو است. (rishe-ye moka’ab-e adad-e hasht do ast.) “The cube root of eight is two.”
- این اتاق ده متر مکعب هواست. (in otâq dah metr-e moka’ab havâst.) “This room has ten cubic metres of air.”
- جعبهای به شکل مکعب بساز. (ja’be-i be shekl-e moka’ab besâz.) “Build a box in the shape of a cube.”
Cultural note
The Arabic mathematical tradition was the primary channel through which classical geometry entered Persian scientific writing during the medieval period, and مکعب is one of many geometric terms that arrived through that route. Persian schoolchildren today encounter the word early in arithmetic class, mostly through the phrase ریشه مکعب (cube root) and the formula for volume. In everyday speech, قند مکعبی, a sugar cube, is the most common context most Iranians meet the word outside of school.