a singularly important sign that something will happen
The sales of durable goods is a key indicator for the economy.
In particular, it will be a key indicator who finishes first.
Wylde also said that tolerance is a “key indicator of opportunity” in any city, state, or county.
Indeed, one key indicator: Since the advent of the euro currency, France has never borrowed at such low rates at it did this week.
And a Better Homes and Gardens survey found that three in four saw homeownership as “a key indicator of success.”