DataReversed is an option for ArrayPlot and related functions that specifies whether data should be plotted in reverse order.

Deployed is an option for displayed objects, cells, and notebooks that specifies whether their contents should be considered deployed, so that elements such as Slider, ...

Deploy[expr] yields a deployed version of expr in which elements such as Slider, InputField, Locator, and Button are active, but general editing and selection is disabled.

DockedCells is an option for notebooks that gives a list of cells that are to be displayed "docked" at the top of the notebook.

DynamicEvaluationTimeout is an option for displayed objects, cells, and notebooks that specifies the timeout in seconds for any Dynamic computations they contain.

EdgeAdd[g, e] makes a graph by adding the edge e to the graph g.EdgeAdd[g, {e_1, e_2, ...}] adds a collection of edges to g.

Evaluatable is an option for Cell that specifies whether a cell should be used as input to be evaluated by the Mathematica kernel.

n!! gives the double factorial of n.

FieldSize is an option for InputField, PopupMenu, and related functions that specifies the size of the field allowed for input or contents.

FourierSeries[expr, t, n] gives the n\[Null]^th-order Fourier series expansion of expr in t. FourierSeries[expr, {t_1, t_2, ...}, {n_1, n_2, ...}] gives the multidimensional ...