Origins
The English word 'box' has a botanical origin that has been almost completely forgotten: it comes from the name of a tree. The word descends from Old English 'box,' borrowed from Late Latin 'buxis' (a container), from Latin 'buxus' (the boxwood tree), from Greek 'pyxos' (πύξος, the boxwood tree). The derived Greek form 'pyxis' (πυξίς) meant specifically 'a container made from boxwood' — a small, round, lidded vessel crafted from the dense, fine-grained, pale wood of the Buxus sempervirens tree, which grew abundantly around the Mediterranean.
The semantic path is clear: the wood gave its name to the container, and the container-name was then generalized to mean any rigid enclosed vessel, regardless of material. By the time Old English borrowed the word (before 1000 CE), the connection to boxwood had already faded in Latin, and 'box' in English has always meant primarily 'container' rather than 'type of wood' — though 'boxwood' as a compound preserves the original meaning.
The phonological shift from Greek 'pyxis' (with initial 'p') to Latin 'buxis' and English 'box' (with initial 'b') reflects the voicing of initial voiceless stops that sometimes occurred in popular Latin borrowings. The learned Latin form 'pyxis,' borrowed separately into English, gives us 'pyx' — the small container used in the Catholic Church to hold the consecrated Eucharist, and also the 'Pyx Chapel' at Westminster Abbey, where standard coins were kept for annual testing. So English has two words from the same Greek source: 'box' (through the popular pronunciation) and 'pyx' (through the learned tradition).
Latin Roots
The boxwood tree itself merits attention. Buxus sempervirens is a slow-growing evergreen shrub or small tree native to Western and Southern Europe, Northwest Africa, and Southwest Asia. Its wood is exceptionally dense (it sinks in water), fine-grained, and pale yellow — ideal for carving, turning, and the production of small, precise objects. In the ancient world, boxwood was used for combs, writing tablets, musical instruments, and, of course, small boxes for medicines, ointments, and cosmetics. The tree's Latin name 'buxus' also gave English 'bush' (by some etymological theories) and is the source of the botanical genus name Buxus.
Across European languages, the word shows a family resemblance. French 'boîte' (box) derives from the same Late Latin 'buxida/buxis.' German 'Büchse' (can, tin, rifle — from the idea of a tube-shaped container) comes from the same source. Dutch 'bus' (can, tin, container — and the source of the English word 'bus,' originally 'omnibus,' though that is from a different Latin word) descends from the same Latin container-word. Italian 'bossolo' (a small box, ballot box) preserves another reflex.
In English, 'box' has been extraordinarily productive. 'Mailbox,' 'sandbox,' 'toolbox,' 'cardboard box,' 'music box,' 'box car,' 'box office,' 'boxing ring,' and 'box set' are just a few of the compounds. 'To box' meaning 'to fight with the fists' is a separate word with an uncertain etymology — it may be related to the idea of a 'box on the ear' (a slap), attested from the fourteenth century, but its ultimate origin is unclear and probably unrelated to the container-word.
Cultural Impact
The figurative uses are equally rich. 'To think outside the box' (to approach a problem creatively) became a business cliche in the 1970s and 1980s, possibly derived from the nine-dot puzzle in which you must extend lines beyond the implied square boundary. 'Pandora's box' (a source of unexpected troubles) is a mistranslation of the Greek myth, in which Pandora opened a 'pithos' (a large storage jar), not a 'pyxis' (a small box) — the mistranslation was introduced by Erasmus of Rotterdam in the sixteenth century when he rendered 'pithos' as 'pyxis' in his Latin version of the myth. 'Boxing Day' (December 26th, a British holiday) is probably named for the Christmas boxes — gifts of money placed in boxes — traditionally given to servants and tradespeople.
The word's journey from a Mediterranean evergreen shrub to a universal container-word is a reminder that many of our most basic everyday terms have origins in the material culture of the ancient world. Every cardboard shipping box and every digital dialog box carries within its name the memory of a Greek craftsman turning a piece of pale, dense wood into a small round container for ointment.