Business index, with "the" (3)
I believe the answer is:
dow
'business index with the' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for dow that I've seen before include "The . . . Jones Index shows the New York Stock Exchange prices" , "The . . . Jones Index gives prices on New York Stock Exchange" , "The ...-Jones Index concerns the New York Stock Exchange" , "The . . .-Jones Index records share prices on New York Stock Exchange" .)