Share market - Meaning of "Unch"

On trading days, before the start of the trading (i.e before 10AM), on TV channel NDTV profit one can see the SENSEX and NSE indices at the bottom right corner. Below the indices they display the word " Unch". Can anyone please let me know the meaning of this word? Note that once the trading starts , these words are replaced by points by which the indices have gone up or down.

Thanks.