From Latin 'fibra' (filament, entrail) — born in Roman augury reading animal guts, now naming everything from diet to optic cables.
A thin, thread-like strand of natural or synthetic material; the essential character or quality of something; dietary material from plants that aids digestion.
From Old French 'fibre' (fiber, filament), from Latin 'fibra' (fiber, filament, entrail, root tip), of uncertain deeper origin. Some scholars have connected it to Latin 'fīlum' (thread), but the phonological relationship is problematic. The word may derive from a pre-Indo-European Mediterranean substrate. In Latin, 'fibra' referred primarily to plant fibers
Roman priests (haruspices) examined the fibrae — the fibrous tissues and entrails — of sacrificed animals to predict the future. The word 'fiber' thus has its origins partly in divination: before it described cotton or dietary roughage, it described the visceral threads through which Romans read the will of the gods. The modern phrase 'moral fiber' (inner strength of character) unknowingly echoes