The ornamental design for a leverhead, as shown and described.
FIG. 1 is a front, top, left perspective view of a lever head showing the new design;
FIG. 2 is a rear, bottom, left perspective view thereof;
FIG. 3 is a left-side elevation view thereof;
FIG. 4 is a right-side elevation view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is top plan view thereof;
FIG. 7 is a front elevation view thereof; and,
FIG. 8 is a rear elevation view thereof.
The broken lines of uneven length shown in the drawings illustrate the boundary of the claimed design and form no part thereof. The broken lines of even length shown in the drawings illustrate portions of the lever head that form no part of the claimed design.