The difference between Impale and Palisade

Impale as a verb (transitive):

To pierce (something) with any long, pointed object.

Impale as a verb (transitive, heraldry):

To place two coats of arms side by side on the same shield (often those of two spouses upon marriage).

Impale as a verb (ambitransitive):

To pierce with a pale; to put to death by fixing on a sharp stake.

Impale as a verb (ambitransitive):

To enclose or fence with stakes.

Palisade as a noun:

A long, strong stake, one end of which is set firmly in the ground, and the other sharpened.

Palisade as a noun:

A wall of wooden stakes, used as a defensive barrier.

Palisade as a noun:

A line of cliffs, especially one showing basaltic columns.

Palisade as a noun (biology):

An even row of cells. e.g.: palisade mesophyll cells.

Palisade as a verb (transitive, usually in the passive):

To equip with a palisade.