I claim the ornamental design for a lubricant stick, as shown and described.
FIG. 1 is a left-side perspective view of a lubricant stick showing my design;
FIG. 2 is a right-side perspective view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a left-side elevation view thereof, it being understood that the opposite side is a mirror image of that shown;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a front elevation view thereof; and,
FIG. 7 is a rear elevation view thereof.
The broken lines shown represent unclaimed subject matter and form no part of the claimed design.
The lubricant stick is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.