"flagging interest" is a correct and usable phrase in written English.
It can be used to describe a decrease or decline in someone's level of interest or enthusiasm about something. Example sentence: Despite initially showing a lot of excitement for the project, her flagging interest in it was evident as she started missing meetings and not meeting deadlines.
Then, a decade or so ago, they added clothes to make up for flagging interest in perfumes alone.
One obvious reason for flagging interest in science fairs is competing demands for high school students' extracurricular attention.
The bank sought Thursday to reassure investors that the two outside investors had shown no signs of flagging interest.
At the same time formula one bosses are trying to boost flagging interest among TV viewers by changing the rules to make the races more exciting.
The shortened format of the game has proved massively popular around the world and Stanford believes it will fuel flagging interest in one of cricket's traditional hotbeds.
American journalists in the 1990s confronted disturbing trends—an erosion of trust in the news media, weakening demand for serious news, flagging interest in politics and civic affairs, and a discouraging public climate that seemed to be getting worse.
Even Rovio seems sort of stuck trying to reignite flagging interests in all things Angry Birds.
If you were with me earlier in the week you might remember that I've flagged interest in whether there will be further government breakouts on this issue as the proposal moves to substantive debate.
That ostensible sign of flagging U.S. interest weakened the U.S. negotiating team's position and reinforced deep-seated resistance to trade liberalization among Japan's political interest groups.
But if flagging public interest in their work is ever to be revived, the Obama administration needs to articulate a bold vision capable of relegitimizing crewed missions, and then back it with real money.
Not only did the show come in at No. 3 in its first hour, but its audience dropped sharply in its second hour, an obvious sign of flagging viewer interest.
