GeoDestination[pos, {d, \[Alpha]}] gives the geodetic position reached by going distance d in azimuthal direction \[Alpha] from pos.
GeometricMeanFilter[image, r] filters image by replacing every value by the geometric mean of the values in its range r neighborhood. GeometricMeanFilter[data, r] applies ...
GroupPageBreakWithin is an option for Cell that specifies whether a page break should be allowed within the group of cells if the notebook that contains the group is printed.
HamiltonianGraphQ[g] yields True if the graph g is Hamiltonian, and False otherwise.
HexadecimalCharacter represents a hexadecimal digit character 0\[Dash]9, a\[Dash]f, A\[Dash]F in StringExpression.
HoldPattern[expr] is equivalent to expr for pattern matching, but maintains expr in an unevaluated form.
Hyphenation is an option for Cell that specifies whether to allow hyphenation for words of text.
Identity[expr] gives expr (the identity operation).
IgnoreCase is an option for string manipulation and searching functions that specifies whether lowercase and uppercase letters should be treated as equivalent.
ImageAssemble[{{image_11, image_12, ...}, {image_21, ...}, ...}] assembles a single image from an array of images.