eight-hour

The compound adjective 'eight-hour' is a modern English formation that transparently combines two ancient elements to specify duration. The first element, 'eight', traces back to the Proto-Indo-European root 'oḱtṓw', a stable numeral that evolved into its Germanic and later Old English form. The second element, 'hour', has a more complex journey from the Greek 'hṓrā', meaning a fixed period or season, which was adopted into Latin and subsequently into the Romance languages before entering English. The fusion of these two morphemes follows a straightforward Germanic compounding pattern, creating a precise, numerical descriptor for a time span, most famously institutionalized in labor movements advocating for an 'eight-hour day'.

Structure: eight (number) + hour (unit of time) - eight: From Old English 'eahta', from Proto-Germanic 'ahtōu', from Proto-Indo-European 'oḱtṓw'. Functions as a numerical quantifier. - hour: From Anglo-Norman 'houre', from Old French 'hore', from Latin 'hōra', from Greek 'hṓrā' (season, time). Functions as a noun indicating a unit of time.