parade、demonstration与procession这些名词均含“游行”之意。

parade : 多指盛大和正式的游行，有检阅等活动。

• a military parade
  军事检阅
• They stood as straight as soldiers on parade.
  他们像接受检阅的士兵一样站得笔直。
• The latest software will be on parade at the exhibition.
  最新电脑软件将在展览会上展出。

demonstration : 侧重指抗议的示威性游行。

• take part in/go on a demonstration
  参加 / 进行示威游行
• to hold/stage a demonstration
  举行示威游行
• mass demonstrations in support of the exiled leader
  支持流亡领导人的群众集会
• anti-government demonstrations
  反政府示威游行
• a peaceful/violent demonstration
  和平 / 暴力示威

procession : 指举行庆祝活动或盛大仪式时庄严行进的有秩序的游行队伍或行列。

• a funeral procession
  送葬的队列
• a torchlight procession
  火炬游行队伍
• The procession made its way down the hill.
  队伍走下山了。
• Groups of unemployed people from all over the country marched in procession to the capital.
  来自全国的失业群众列队向首都进发。