A flag, as I'm sure you know, is a piece of cloth used as a symbol of a country or organisation. Such flags can also be used to send messages or signals. You can flag up something for attention, or flag down a taxi.
Flat stones used for paving are sometimes known as flags. To flag is to become tired or less enthusiastic. Flag is also a type of iris.
Is there anything you can think of that I should have flagged, but didn't? Ah yes, another free to enter writing contest.
How about this one? You have to email the oraniser for an entry for. Three cash prizes are on offer, with £50 for first place. Stories up to 3,000 words are accepted.