bordering, bounding, edging, framing, fringing, rimming, skirting

hemming, trimmingcircumscribing, defining, delineating, demarcating, outlining, silhouetting, sketching, tracingcircling, compassing, encircling, enclosing(also inclosing), environing, girdling, girthing, looping, ringing, rounding, surrounding, wallingchecking, confining, controlling, curbing, limiting, restraining, restricting