Deletable is an option for Cell that specifies whether the cell can be deleted interactively using the front end.

DeleteContents is an option for DeleteDirectory that specifies whether the contents of directories should automatically be deleted.

DeleteDirectory["dir"] deletes the specified directory.

DeleteDuplicates[list] deletes all duplicates from list.DeleteDuplicates[list, test] applies test to pairs of elements to determine whether they should be considered ...

Delete[expr, n] deletes the element at position n in expr. If n is negative, the position is counted from the end. Delete[expr, {i, j, ...}] deletes the part at position {i, ...

DeletionWarning is an option for InterpretationBox or TagBox objects that specifies whether a warning is issued if the box is deleted.

DelimiterFlashTime is an option for cells and notebooks that specifies how long in seconds a delimiter should flash when its matching delimiter is entered.

DelimiterMatching is an option for selections that specifies whether an opening delimiter will match only its respective closing delimiter or any closing delimiter.

Denominator[expr] gives the denominator of expr.

DensityHistogram[{{x_1, y_1}, {x_2, y_2}, ...}] plots a density histogram of the values {x_i, y_i}.DensityHistogram[{{x_1, y_1}, {x_2, y_2}, ...}, bspec] plots a density ...