The ornamental design for a retractableknife, as shown and described.
FIG. 1 is a left side frontal-perspective view of a retractable knife of an embodiment of the inventive concept.
FIG. 2 is a top plan view of the retractable knife of FIG. 1.
FIG. 3 is right side elevation view of the retractable knife of FIG. 1.
FIG. 4 is a bottom plan view of the retractable knife of FIG. 1.
FIG. 5 is a left side elevation view of the retractable knife of FIG. 1.
FIG. 6 is a rear elevation view of the retractable knife of FIG. 1.
FIG. 7 is a front elevation view of the retractable knife of FIG. 1.
FIG. 8 is a detail view of a portion of the retractable knife of FIG. 1 taken from area “FIG. 8” of FIG. 1, the opposing side being a mirror image thereof; and,
FIG. 9 is a detail view of a portion of the retractable knife of FIG. 1 taken from area “FIG. 9” of FIG. 8, the opposing side being a mirror image thereof.