ForwardBackward is a symbol that represents alternate forward and backward motion or animation.
FrameBoxOptions -> {opt_1 -> val_1, opt_2 -> val_2, ...} is an option for cells that specifies default settings.
FrobeniusNumber[{a_1, ..., a_n}] gives the Frobenius number of a_1, ..., a_n.
GraphicsGroup[{g_1, g_2, ...}] represents a collection of graphics objects grouped together for purposes of interactive selection in a notebook.
GreaterFullEqual[x, y, ...] displays as x \[GreaterFullEqual] y \[GreaterFullEqual] ....
GreaterGreater[x, y, ...] displays as x \[GreaterGreater] y \[GreaterGreater] ....
GreaterLess[x, y, ...] displays as x \[GreaterLess] y \[GreaterLess] ....
GreaterSlantEqual[x, y, ...] displays as x \[GreaterSlantEqual] y \[GreaterSlantEqual] ....
GreaterTilde[x, y, ...] displays as x \[GreaterTilde] y \[GreaterTilde] ....
Green
(Built-in Mathematica Symbol) Green represents the color green in graphics or style specifications.