silicium

[suh-lish-ee-uh m, suh-lis-] /səˈlɪʃ i əm, səˈlɪs-/
noun, (formerly)
1.
Origin
1800-10; < Neo-Latin; see silica, -ium
British Dictionary definitions for silicium

silicium

/sɪˈlɪsɪəm/
noun
1.
a rare name for silicon