greku -rek- gismu

x1 is a frame/structure/skeleton/outline supporting/load-bearing/determining the form of x2.

See also korbi, stura, tsina, bongu.

In notes:

bongu
x1 is a/the bone/ivory [body-part], performing function x2 in body of x3; [metaphor: calcium].
korbi
x1 is an edge/margin/border/curb/boundary of x2 next-to/bordering-on x3.
stura
x1 is a structure/arrangement/organization of x2 [set/system/complexity].
tsina
x1 is a stage/platform/dais/[scaffold] at/in x2 supporting x3, made of material x4.
ga'argreku
x1 is a truss for supporting x2
ji'erslegreku
x1 is the cytoskeleton of cell x2
rekyuidje
u1=g1 is a frame enclosing widget(s) g2 in user interface u2
zbadjurek
x1 is a scaffolding for building x2