el querellante, la querellante - plaintiff in a legal action (typically the one who files a lawsuit)Spanish example: Los querellantes en caso Pinochet piden que se amplie el tiempo de sus alegatos.
English example: The plaintiffs in the Pinochet case are asking that the time for their pleas be lengthened.
Source: el querellante, la querellante - plaintiff in a legal action (typically the one who files a lawsuit) (https://www.123teachme.com/spanish_feeds/word_of_the_day/2020/7/6)