The ornamental design for a ceilingfan, as shown and described.
FIG. 1 is a bottom/front/right perspective view of the ceiling fan, for which the bottom/rear/left perspective view is identical;
FIG. 2 is a top/front/right perspective view of the ceiling fan, for which the top/rear/left perspective view is identical thereto;
FIG. 3 is a bottom plan view of the ceiling fan;
FIG. 4 is a front elevational view of the ceiling fan, for which the rear elevational, left side elevational, and right side elevational views are identical; and,
FIG. 5 is a top plan view of the ceiling fan.
The broken lines represent environment and form no part of the claim.