静粛【せいしゅく】
silent
粛清【しゅくせい】
(political) purge
自粛【じしゅく】
self-restraint, voluntary restraint, self-imposed control, self-discipline
厳粛【げんしゅく】
grave, solemn, serious, harsh (e.g. truth), hard, strict
綱紀粛正【こうきしゅくせい】
enforcement of official discipline, tightening of discipline, eliminating corruption among government officials
粛正【しゅくせい】
regulation, enforcement
粛軍【しゅくぐん】
army purge