Half-mast (British, Canadian and Australian English) or half-staff (American English) refers to a flag flying below the summit of a ship mast, a pole on land, or a pole on a building. In many countries this is seen as a symbol of respect, mourning, distress, or, in some cases, a salute.
A flag that is at half mast has been brought down to a point halfway down the pole as an expression of sadness at someone's death:
The flags at Buckingham Palace were all flying at half-mast.
Covid: Biden calls 500,000 death toll 'a grim milestone'
President Joe Biden addressed the nation as the US marks 500,000 deaths from Covid, the most for any country in the world.
"As a nation, we can't accept such a cruel fate. We have to resist becoming numb to the sorrow," he said.
The president and vice-president, and their spouses, then observed a moment of silence outside the White House during a candle-lighting ceremony.
More than 28.1 million Americans have been infected - another global record.
President Biden ordered all flags on federal property to be lowered to half mast for the next five days.
"We have so much capability, so many resources in this country... this was all preventable and should not have happened. And yet here we are," he told BBC News on Monday. "And I think we have to reflect on all the ways in which our response went wrong."
