From AMS Glossary
A mass of gas suspended over the chromosphere by magnetic fields and seen as dark ribbons threaded over the solar disk. They consist of higher-density and lower-temperature material than the surrounding corona. A filament that displays motion or changes in shape, location, or absorption characteristics is known as an active dark filament (ADF). A filament that disappears on timescales ranging from minutes to hours is known as disappearing solar filament (DSF). A filament on the limb of the sun seen in emission against the dark sky is called a prominence.
Term edited 14 August 2018.