Flag (noun)

1. A piece of cloth, typically rectangular, bearing a design, symbol, or other device and used as a symbol of a nation, organization, or other entity.
2. A piece of cloth used as a signal or symbol.
3. A marking used to indicate the beginning or end of a particular part of a race or competition.
4. A drooping or falling off of power, strength, or energy.

Origin:

Middle english: from old norse flaga "a flagstone"; related to middle low german vlak "a flat piece".

Examples:

1. The national flag was flying at half-mast.
2. The Olympic flag was carried into the stadium.
3. The runner crossed the finish line and collapsed, his strength flagged.
4. The flag at the top of the pole was blowing in the wind.
5. The flag was a symbol of hope for the country's future.