The Greek letter omega is the symbol for this unit of electrical resistance
In the ... For ohm  SI unit 
of electrical resistance; formerly also used upside down () to represent mho, the 
old name for the... [DOC] [TLE] Greek letters used in mathematics, science, and engineering ... [PAR] the SI unit measure of electrical resistance, the ohm  angular velocity ... the 
symbol , a graphic variant of , is sometimes construed as ...  (omega) 
position, reflecting that  is the last letter of the Greek alphabet.