The ornamental design for an electrode, as shown and described.
FIG. 1 is a top perspective view of my new design for an electrode in the preferred embodiment, wherein the dotted lines show an outline of a drainage stand and a power cord which is for illustrative purposes only and is not part of the claimed design.
FIG. 2 is a front elevation view of the electrode of FIG. 1, wherein the dotted lines show an outline of a power cord which is for illustrative purposes only and is not part of the claimed design.
FIG. 3 is a rear elevation view of the electrode of FIG. 1, wherein the dotted lines show an outline of a power cord which is for illustrative purposes only and is not part of the claimed design.
FIG. 4 is a bottom plan view of the electrode of FIG. 1, wherein the dotted lines show an outline of a power cord which is for illustrative purposes only and is not part of the claimed design; and,
FIG. 5 is a top plan view of the electrode of FIG. 1, wherein the dotted lines show an outline of a power cord which is for illustrative purposes only and is not part of the claimed design.