The word 'wax' (the substance) descends from Old English 'weax' (beeswax), from Proto-Germanic *wahsą, from PIE *wokso- (wax). The word is remarkably well preserved across the Indo-European family: German 'Wachs,' Dutch 'was,' Swedish 'vax,' Old Norse 'vax,' Russian 'vosk' (воск), Polish 'wosk,' Lithuanian 'vaškas,' and Old Church Slavonic 'vosk' all descend from the same PIE root. This broad distribution across both the Germanic and Balto-Slavic branches strongly supports a PIE origin and suggests that the Proto-Indo-Europeans were already familiar with beeswax and beekeeping.
The PIE etymon *wokso- has been tentatively connected to *weg- (to weave), which would make wax 'the woven substance' — a reference to the hexagonal honeycomb structure that bees construct from their secretion. This connection is semantically attractive but phonologically uncertain.
Beeswax was one of the most valuable natural substances in the ancient and medieval world. It was the only material that could produce clean-burning, smokeless candles (tallow candles smoked and smelled). Churches consumed enormous quantities of beeswax candles, and beeswax was an important trade commodity and tax payment throughout medieval Europe. The phrase 'none of your beeswax' (mind your own business) may derive from a time when beeswax was a serious commodity
The word 'wax' originally referred exclusively to beeswax and retained this narrow meaning for most of its history. The extension to other waxy substances — paraffin wax (derived from petroleum, discovered in the 1820s), carnauba wax (from a Brazilian palm), and various synthetic waxes — is a modern development. 'Earwax' (cerumen) uses 'wax' metaphorically, based on the substance's waxy texture.
A notable feature of English is the existence of two completely unrelated words spelled 'wax.' The noun 'wax' (beeswax, from PIE *wokso-) and the verb 'to wax' (to grow, to increase, to become — from Old English 'weaxan,' from PIE *h₂weg-, to increase, to grow) are etymological strangers whose forms converged through sound changes. 'The waxing moon' uses the verb (the moon is growing). 'To wax poetic' means to become increasingly poetic. 'To wax and wane' pairs growth and decline. None of these have any connection to beeswax.
Wax seals — impressions made in melted wax to authenticate documents — were the primary means of verifying identity and securing correspondence from antiquity through the 19th century. The phrase 'sealed with a kiss' may owe something to the wax-sealing tradition. 'Sealing wax' is technically not beeswax but a mixture of shellac and resin, though the 'wax' name stuck. Madame Tussauds waxworks — lifelike figures molded in wax — preserve another ancient use of the material: wax as a sculpting medium, exploiting its low melting point and fine detail retention.