The ornamental design for an undergarmentstrap, as shown and described.
FIG. 1 is a front isometric view of an embodiment of the undergarment strap showing my new design in a shortened configuration such that the overall size of the strap is smaller.
FIG. 2 is a rear elevation view thereof in a lengthened configuration such that the overall size of the strap is larger.
FIG. 3 is a front isometric view of an embodiment of the undergarment strap of FIGS. 1 and 2, as it may appear when worn.
FIG. 4 is a rear isometric view thereof.
FIG. 5 is a front view thereof in an alternate position when worn.
FIG. 6 is a rear view thereof; and,
FIG. 7 is an enlarged view of a portion of the undergarment strap of FIG. 1.
The broken lines shown as part of the strap adjusters to the posture enhancement strap do not form a part of the claimed design. The partial human figure shown in broken lines is environmental subject matter included to help illustrate how the design appears when worn and forms no part of the claimed design. The broken-line circle shown in FIGS. 1 and 7 depict the bounds of the enlarged view of FIG. 7.