From OldNorse 'báðir,' PIE *bʰóh₁ — it replaced native Old English 'bā' and is related to Greek 'amphi-' and Latin 'ambō.'
Definition
Used to refer to two people or things, regarded and identified together.
The Full Story
Old Norse12th centurywell-attested
From OldEnglish bā, bēgen (both), reinforced or replaced in Middle English by Old Norse bāðir (both), from Proto-Germanic *baiz (both), from the PIE root *bʰoh₂ (both), an emphatic dual form related to *dwóh₁ (two). The PIE dual number — a grammatical category for pairs, distinct from singular and plural — was once a living feature of Indo-European languages, preserved in Sanskrit, Ancient Greek, Old Church Slavonic, and Gothic. Both is a fossil of this dual system: it originally agreed
Did you know?
English 'both,' Latin 'ambō,' andGreek 'amphō' all descend from the same PIE root *bʰóh₁. The Greek form 'amphi-' (on both sides) hides inside 'amphibian' (living on both sides — land and water), 'amphitheater' (a theater with seating on both sides), and 'amphora' (a jar with handles on both sides). Latin 'ambō' gives 'ambiguous' (going both ways) and 'ambidextrous' (right
). Many fundamental English words were reshaped or replaced by Norse cognates during this era: they, them, their, take, get, give, and both itself. The word's survival across millennia as a dual marker makes it a living linguistic fossil — a remnant of a grammatical system that Indo-European has otherwise largely abandoned. Key roots: *bʰóh₁ (Proto-Indo-European: "both").