The ornamental design for underwear, substantially as shown and described.
FIG. 1 is a front exterior view of underwear in accordance with the present invention shown in a first embodiment.
FIG. 2 is a front interior view thereof.
FIG. 3 is a rear exterior view thereof.
FIG. 4 is a rear interior view thereof.
FIG. 5 is a front exterior view of underwear in accordance with the present invention shown in a second embodiment.
FIG. 6 is a front interior view thereof.
FIG. 7 is a rear exterior view thereof; and,
FIG. 8 is a rear interior view thereof.
The broken lines shown in the drawings depict portions of the underwear that form no part of the claimed design. The shaded portions of each embodiment represent contrasting colors.