The ornamental design for a chairarm, as shown and described.
FIG. 1 is a perspective front exterior side view of the chair arm;
FIG. 2 is a perspective front interior side view of the chair arm;
FIG. 3 is an exterior side view of the chair arm;
FIG. 4 is an interior side view of the chair arm;
FIG. 5 is a top view of the chair arm;
FIG. 6 is a bottom view of the chair arm;
FIG. 7 is a rear view of the chair arm;
FIG. 8 is a front view of the chair arm; and,
FIG. 9 is a perspective front side view of the chair arm used as both right and left chair arms, showing the position of the chair back and chair seat and leg support positioned therebetween.
The broken line shown in FIGS. 6 and 9 are for illustrative purposes only and forms no part of the claimed design.