sakli -sal- gismu

x₁ slides/slips/glides on x₂.

x₂ is slick/slippery to/for x₁ (= selsakli for reordered places). See also mosra, fulta, skiji, xutla.

In notes:

fulta: x₁ (passive) floats on/in fluid (gas/liquid) x₂; x₁ is buoyant.
mosra: x₁ is friction [force opposing motion] due to contact/rubbing between x₂ and x₃; (fe) x₂ rubs x₃.
muxne: x₁ is slime/mucus/ooze produced by x₂
salcpare: x₁ slithers on surface x₂ in direction x₃ using limbs x₄.
salvoi: x₁=s₁=v₁ glides (unpowered flight) on x₂=s₂ (typically an air current).
skiji: x₁ is a ski/skid/skate/runner for surface (of material) x₂ supporting skier/skater/sled/cargo x₃.
tumsaljau: x₁ is stormwater runoff at x₂.
xutla: x₁ is smooth/even/[soft/silky] in texture/regularity.