The ornamental design for an elasticwaistband, as shown and described.
FIG. 1 is a top-front-left perspective view of an elastic waistband showing my new design, the top-front-right perspective view being mirrored thereto;
FIG. 2 is a top-rear-right perspective view thereof, the top-rear-left perspective view being mirrored thereto;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof; and,
FIG. 5 is a left-side elevational view thereof, the right-side elevational view being mirrored thereto.
The broken line showing an exemplary undergarment is included for the purpose of illustrating environmental structure and forms no part of the claimed design.