The ornamental design for toothbrush, as shown and described.
FIG. 1 is a front elevational view of toothbrush embodying my new design;
FIG. 2 is a left side elevational view thereof, the right side elevational
view being a mirror image of the side shown; and,
FIG. 3 is a rear elevational view thereof.
The portions of the top and bottom of the toothbrush neither shown in the
drawing nor described in the specification form no part of the claimed
design.
The drawings are lined and shaded to show a contrast in color.