h₂embʰi
“around, on both sides”around
PIE preposition meaning around or on both sides. Source of Latin ambi-, Greek amphi, and English "both."
Discussion
*h₂embʰi is a Proto-Indo-European preposition meaning "around" or "on both sides," one of the fundamental spatial morphemes of the proto-language.
Latin ambi- "on both sides, around" yields English ambiguous ("going both ways"), ambidextrous, ambient, and ambition (originally "going around" canvassing for votes). Greek amphí "around, on both sides" gives English amphi- (amphitheater, amphibian—"living on both sides," i.e., land and water, amphora).
Old Irish imb- "around" and Welsh am- continue the Celtic form. Old High German umbi (modern German um "around") reflects the Germanic reflex, as does Old English ymbe "around."
Sanskrit abhí "toward, around" shows the Indo-Iranian development. The initial laryngeal *h₂ is reflected in the a-vocalism, while the *-bʰi ending may be related to the PIE instrumental suffix.
The root encodes the concept of bilaterality and encirclement, making it fundamental to expressions of surrounding, duality, and comprehensive scope. Modern descendants include English ambiguous, ambidextrous, ambient, amphibian, amphitheater, and the German preposition um.
Notes
Source of Latin "ambi-", Greek "amphí", English "by". Circumlocational.