Isang Bagsak! in English - One Down! a practice to show unity by Anti Martial Law activist in th Philippines.
It was also used by the Delano Manongs in the fight for the Farm Workers Movement. The unity clap starts as a slow clap and builds up to a faster pace thats reach a climax of a call to "Isang Bagsak!" which the community ends with a united clap and or a stomp.