(chemistry) The least reactive of the allotropes of phosphorus; it has no significant commercial use.

A Friday falling on the 13th day of the month (and therefore doubly ill-omened). / (possibly obsolete) Good Friday. / Any Friday actually darkened by catastrophe, or the anniversary thereof.

A species of truffle, Tuber melanosporum, darker than the white truffle, most commonly from France but also found in other parts of Europe, that is prized as a culinary ingredient.

(film) To end a film or a scene of a film by causing the image to be gradually dimmed into black.

(film) An ending of this kind.

(chemistry) A form of carbon black formed by the decomposition (but not by the burning) of acetylene. It is characterized by its high degree of crystalline orientation compared with other sources of carbon black.

A perennial member of the sunflower family (Asteraceae), cultivated as a root vegetable (Pseudopodospermum hispanicum, syn. Scorzonera hispanica).

A black-shelled edible mollusc (Haliotis crachedorii), found off the North American Pacific coast.

(astronomy) A hypothesized white dwarf that has cooled down and no longer emits visible light.

(Ireland, UK, idiomatic, potentially offensive) Third-world charities, the missions.