[Right-click] > Speak Selection (Mathematica Menu Item)

Speak Selection speaks the contents of a single selected cell.

Insert > Table/Matrix > Split Spanning (Mathematica Menu Item)

Split Spanning divides a spanning entry from a formatted grid into separate entries.

Cell > Convert To > StandardForm Display (Mathematica Menu Item)

StandardForm Display displays a selection in Mathematica StandardForm.

Evaluation > Debugger Controls > Step (Mathematica Menu Item)

Step makes the debugger stop at the beginning of the next expression.

Cell > Convert To > Text Display (Mathematica Menu Item)

Text Display displays the selection as plain text without interpreting it.

Cell > Convert To > TraditionalForm ... (Mathematica Menu Item)

TraditionalForm Display displays the selection in Mathematica TraditionalForm

Help > Wolfram Website... (Mathematica Menu Item)

Wolfram Website opens the main Wolfram Research website in a web brower.

CellSize (Built-in Mathematica Symbol)

CellSize is an option for cells that specifies the width and height of an inline cell.

DefaultStyleDefinitions (Built-in Mathematica Symbol)

DefaultStyleDefinitions is a global option that specifies the default stylesheet for all new notebooks.

Dithering (Built-in Mathematica Symbol)

Dithering is an option for ColorQuantize that specifies whether or not to apply dithering while quantizing the pixel values.