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orbit – n. the curved path that something (such as a moon or satellite) follows as it goes around something else (such as a planet)
signal – n. something (such as a sound, a movement of part of the body, or an object) that gives information about something or that tells someone to do something
sanction – n. an action that is taken or an order that is given to force a country to obey international laws by limiting or stopping trade with that country, by not allowing economic aid for that country, etc. (usually plural)
track – n. the course along which someone or something moves or proceeds
