cukla -cuk- gismu

x₁ is round/circular [2-dimensional shape/form]; x₁ is a disk/circle/ring.

Normally used for a filled-in circle/disk, but emphasis on roundness means that the concept may include 'ring'. See also djine, ranji, bolci, tarmi.

In notes:

bolci: x₁ is a ball/sphere/orb/globe [shape/form] of material x₂; x₁ is a spherical object [made of x₂].
djine: x₁ is a ring/annulus/torus/circle [shape/form] of material x₂, inside diam. x₃, outside diam. x₄.
ranji: x₁ (event/state) continues/persists over interval x₂; x₁ (property - ka) is continuous over x₂.
tarmi: x₁ [ideal] is the conceptual shape/form of object/abstraction/manifestation x₂ (object/abstract).
caltaicmaci: cm₁ is a geometry describing cm₂=ca₁=t₁ geometric object.
cukcartu: x₁ is a pie-chart of/about x₂ showing formation/data-points x₃.
cukli'u: l₁ goes/moves around/[in a circle] using means l₃.
cukrerkavjvi: j₁ plays ultimate frisbee against j₂ in competition j₃ for prize/title j₄.
cukseltai: t₁=c₁ is an circle-shaped / circular object.
cuktaima'arbi'i: j1 is a cirque/corrie/cwm between mountains/hills c1=j2 in terrain c2
cuktermai: m₃=c₁ is a disc [circular physical object] made of a material m₁.
cukydagyterkruca: x1=k3 is a roundabout of road x2=d1
relcuktai: t₁=c₁ is a double circle.