The ornamental design for a lighter, as shown and described.
FIG. 1 is a first perspective view of a lighter showing my new design;
FIG. 2 is a second perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a back view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top view thereof;
FIG. 8 is a bottom view thereof; and,
FIG. 9 is an enlarged view of the selected portion in FIG. 1.
The broken lines consisting of evenly spaced dash lines in the drawings depict portions of the lighter that form no part of the claimed design; the broken lines consisting of short and long dash lines encircling the enlarged detail views are for annotative purposes that form no part of the claimed design.