Wiktionary
box kick
n. (context rugby English) A type of kick performed by the scrum-half (or very rarely acting scrum-half). From the base of a ruck, maul or scrum, the scrum-half will stand sideways onto the opposition with his kicking foot further from them, and kick the ball high into the air so as to hopefully prevent the opposition charging down the kick. vb. to kick the ball in the manner described above.