The ornamental design for an axehead, as shown and described.
FIG. 1 is a perspective view of an axe head;
FIG. 2 is a right elevation view of the axe head of FIG. 1;
FIG. 3 is a left elevation view of the axe head of FIG. 1;
FIG. 4 is a rear elevation view of the axe head of FIG. 1;
FIG. 5 is a front elevation view of the axe head of FIG. 1;
FIG. 6 is a top plan view of the axe head of FIG. 1; and,
FIG. 7 is a bottom plan view of the axe head of FIG. 1.
The broken lines in the figures are for the purposes of illustrating portions of the axe head or environmental structure and form no part of the claimed design.