lasna -la'a- gismu

x1 (agent) fastens/connects/attaches/binds/lashes x2 to x3 with fastener x4.

No implication that result is considered a single object; although x2 and x3 may be reversible, x3 may be used for the substrate, the fixed/larger object to which x2 becomes attached. See also jorne, fenso, jgena, batke, dinko, kansa.

In notes:

batke
x1 is a button/knob/[handle] on/for item x2, with purpose x3, made of material x4.
dandu
x1 hangs/dangles/is suspended from x2 by/at/with joint x3.
dinko
x1 is a nail/tack [pointed driven/frictional fastener] of type/size x2 (ka), made of material x3.
fenso
x1 sews/stitches/sutures materials x2 (ind./set) together with tool(s) x3, using filament x4.
jgena
x1 is a knot/tangle in/between x2 (object/jo'u-objects).
jorne
x1 is joined to/connects to/is united with x2 at common locus x3; x1 and x2 are a union.
kansa
x1 is with/accompanies/is a companion of x2, in state/condition/enterprise x3 (event/state).
jongau
g1 (agent) causes j1 to be joined to/connected to/united with j2 at common locus j3.
la'arpu'i
x1 plants x2 on/at surface/locus x3
klupanido
x1 is an occlupanid of species x2.