To encircle is to surround, or to make a circle around. On the last night of summer camp, the counselors and campers traditionally encircle the campfire and sing songs.
Prisons are encircled by barbed wire fences, and hot, damp pavement encircles most public swimming pools. When you hug your little sister, you encircle her with your arms. If your tomato plants are growing too tall and flopping over, you should encircle them with twine to hold them up. Encircle adds the prefix en-, "make or put in" to circle, from its Latin root circus, or "ring."