"Being sent down" can have several synonyms depending on the context it is used in. In a legal context, it can be replaced with "sentenced", "convicted" or "jailed". In a sports context, it can be substituted with "demoted", "relegated" or "dropped". In a workplace context, "being let go" or "terminated" can be used. Other synonyms can include "dismissed", "banished", or "exiled" depending on the situation. Regardless of the context, the underlying meaning remains the same - to be removed or isolated from a certain environment or activity due to disciplinary or performance issues.