The ornamental design for a defibrillator with cover, as shown and described.
FIG. 1 is a perspective view of a defibrillator with cover;
FIG. 2 is a front view thereof;
FIG. 3 is a left-side view thereof, the right-side view being a mirror image thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a top view thereof; and,
FIG. 6 is a bottom view thereof.
The oblique lines in FIGS. 1-3 and 5 indicate transparency of the cover, and the broken lines in the Figures indicate unclaimed environmental structures.