Flag at half-staff and Half-mast

Half-mast and flag at half-staff are semantically related. In some cases you can use "Half-mast" instead a noun phrase "Flag at half-staff".

Half-mast noun - A position some distance below the top of a mast to which a flag is lowered in mourning or to signal distress.

Flag at half-staff and half-mast are semantically related. You can use "Flag at half-staff" instead a noun phrase "Half-mast".