It’s amount of income via dividends expected from the security over the next 12 months, assuming the company pays future dividends as they’ve paid past ones.
Investopedia has has a definition:
“An indicated dividend is the estimated amount of cash dividends that will be paid on a share of stock during the next 12 months based on the dividends that were paid in the past. It is a projection, or estimate, of future income potential based on the company’s prior track record of paying dividends.”