'Silicon' is Latin for 'the flint element' — from 'silex' (flint). Not to be confused with silicone.
The chemical element of atomic number 14, a non-metal with semiconducting properties, used in making electronic circuits.
From Latin 'silex' (flint, hard stone, pebble, silica), genitive 'silicis,' of uncertain ultimate etymology — possibly from a pre-Latin Mediterranean substrate language, as the word does not map cleanly onto PIE roots. Silicon (Si, atomic number 14) was named in 1817 by the Scottish chemist Thomas Thomson, following the model of 'carbon' and 'boron' (both ending in '-on' to suggest a non-metallic element). The underlying mineral is silica (silicon dioxide, SiO₂), the compound that comprises quartz, sand, and flint. Latin 'silex' thus gave the world both the ancient name for flint — the fire-making
'Silicon' (the element) and 'silicone' (the synthetic material) are different things with confusingly similar names. Silicon is an element — the stuff of computer chips and sand. Silicone is a synthetic polymer containing silicon — the stuff of kitchen utensils and breast implants. 'Silicon Valley' (the tech hub) is named for the element in its chips. 'Silicone Valley' would be a very different place.