korbi -kor-koi- gismu

x₁ is an edge/margin/border/curb/boundary of x₂ next-to/bordering-on x₃.

See also cmavo list koi, greku, mlana, jimte, ctebi, bartu.

In definition:

bartu: x₁ is on the outside of x₂; x₁ is exterior to x₂.
ctebi: x₁ is a/the lip [body-part]/rim of orifice x₂ of body x₃; (adjective:) x₁ is labial.
greku: x₁ is a frame/structure/skeleton/outline supporting/load-bearing/determining the form of x₂.
jimte: x₁ is a limit/extreme/bound/border/[confinement] of x₂ in property/domain x₃.
mlana: x₁ is to the side of/lateral to x₂ and facing x₃ from point of view/in-frame-of-reference x₄.
blotcana: t₁ is a seaport/ferry terminal in transport system t₂ for boats/ships/vessels of type b₂ propelled by b₃.
dagykoi: x₁=k₁ is a curb/kerb of x₂=k₂=d₁
drukorni'a: x₁=k₁=n₁ (individual or mass) is the eave of roof x₂=k₂=n₂=d₁
koidru: k₁ is an overhanging portion of roof d₁=k₂, which is a roof of d₂.
plinyxabykoi: k₁ is the equator of planet x₂=p₁ (default Earth) revolving around p₂
ri'erkoi: k₁ is a bank of river k₃=r₁.
selbancu: x₂=b₁ exceeds/is beyond limit/boundary x₁=b₂ from x₃=b₃ in property/amount x₄=b₄ (ka/ni).
vrokoi: k₁=v₁ is the threshold defining access through the boundary between k₂=v₂ and k₃=v₃.