1: Of little or no consequence: trifling, inconsequential
2: Having no force : inoperative
Nugatory comes from the Latin adjective nugatorius and is ultimately a derivative of the noun nugae, meaning "trifles."
To cast off something regarded as unwanted or burdensome. The act of discarding something.
Originally, jettison was the act of throwing goods overboard to lighten a ship in distress. From Latin jactare (to throw), frequentative of jacere (to throw). Ultimately from the Indo-European root ye- (to throw), which also gave us jet, eject, project, reject, object, subject, adjective, joist, jactitation,subjacent, and jaculate.