petitioner

名词 petitioner:

1. one praying humbly for something
   同义词：suppliant, supplicant, requester
2. someone who petitions a court for redress of a grievance or recovery of a right
   同义词：suer

1. The petitioner ask for a variation in her maintenance order.
   上诉人要求对她生活费的命令的条件进行变更。