applause (noun) as on Earth, a sign of approval; on Gor, however, it is performed by striking the right hand against the left shoulder, or, by Warriors in Arms, by the striking of sword or spear against shield.

There was applause, the striking of the left shoulder, from the tables. The brute then crouched beside her and encircled her neck with the coils of his whip. He drew her to her knees then before him. She looked up at him, her neck in the whip coils, his. There was more applause. Then the brute looked to Policrates, who indicated a table. He then pulled the girl to her feet and, running her over the tiles, and then releasing the coils from her neck, threw her stumbling into the arms of waiting pirates who, with a cry of pleasure, sized her and began to work their lusty wills upon her. There was more applause, and laughter. 
Book 15, Rogue: pg 191

There was applause for this at the table, the gentle striking of left shoulders, for she had done it well, and the significance of a woman's unbinding her hair before a man is well understood on Gor. 
Book 16, Guardsmen: pg 247

There was a shout of pleasure from the men. They were striking their left shoulders with their right fists, repeatedly, in Gorean applause. 
Book 8, Hunters: pg 94

The girls howled with laughter, and slapped their left shoulders with the palms of their right hands. He bowed to them and, gravely, left the circle. They continued to slap their shoulders with pleasure. 
Book 7, Captive: pg 66

There was some polite striking of the left shoulder with the right hand in the room, which is a common Gorean applause, though not of the warriors, who clash weapons. 
Book 6, Raiders: pg 173