stock index
noun[C]
FINANCE,STOCK MARKETukus(alsostock market index);(alsoshare index)aseriesofnumbersthatshowschangesin theaveragepricesofshareson aparticularstockmarketovertime:
The Nikkei 225stockindexsurged2% lastweek
Themainstockindexwas down 350points.