Si
n 1: a tetravalent nonmetallic element; next to oxygen it is the
most abundant element in the earth's crust; occurs in
clay and feldspar and granite and quartz and sand; used
as a semiconductor in transistors [syn: {silicon}, {Si},
{atomic number 14}]
2: a complete metric system of units of measurement for
scientists; fundamental quantities are length (meter) and
mass (kilogram) and time (second) and electric current
(ampere) and temperature (kelvin) and amount of matter
(mole) and luminous intensity (candela) [syn: {Systeme
International d'Unites}, {Systeme International}, {SI}, {International
System}]
3: the syllable naming the the seventh (subtonic) note of any
musical scale in solmization [syn: {ti}, {te}]