The ornamental design for a collapsiblehat, as shown and described.
FIG. 1 is a front elevation view of my new design for a collapsible hat;
FIG. 2 is a left side elevation view of the hat shown in FIG. 1;
FIG. 3 is a rear elevation view of the hat shown in FIG. 1;
FIG. 4 is a right side elevation view of the hat shown in FIG. 1;
FIG. 5 is a top plan view of the hat shown in FIG. 1; and,
FIG. 6 is a bottom plan view of the hat shown in FIG. 1.
The broken lines showing retention straps and strap anchors are included for the purpose of illustrating environmental structure only, and form no part of the claimed design. The fine broken lines show stitching as part of the design.