Si

from WordNet (r) 3.0 (2006)

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); "Today the United States is
       the only country in the world not totally committed to the
       Systeme International d'Unites" [syn: {Systeme International
       d'Unites}, {Systeme International}, {SI system}, {SI}, {SI
       unit}, {International System of Units}, {International
       System}]
    3: the syllable naming the seventh (subtonic) note of any
       musical scale in solmization [syn: {ti}, {te}, {si}]

from The Collaborative International Dictionary of English v.0.48

Si \Si\ [It.] (Mus.)
   A syllable applied, in solmization, to the note B; more
   recently, to the seventh tone of any major diatonic scale. It
   was added to Guido's scale by Le Maire about the end of the
   17th century.
   [1913 Webster]

from The Collaborative International Dictionary of English v.0.48

Maffioso \Maf`fi*o"so\, Mafioso \Ma`fi*o"so\, n.; pl. {-si}.
   [It. maffioso.]
   A member of the mafia.
   [Webster 1913 Suppl.]

from The Free On-line Dictionary of Computing (8 July 2008)

SI

   1. <unit> {Système International}.

   2. <character> {Shift In}.

from The Free On-line Dictionary of Computing (8 July 2008)

si

   <networking> The {country code} for Slovenia.

   (1999-01-27)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

SI
       Schweizer Informatikergesellschaft (org., Switzerland)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

SI
       Skyrslutaeknifelags Islands (org., Iceland)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

SI
       Source Index [register] (CPU, Intel, assembler)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

SI
       SPARC International (org., manufacturer)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

SI
       System Identifier (DTD, URI, SGML, FPI)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

SI
       System Information