In general means, assign an inferior rank or position to someone / something. Also depending on situation, it can be defined as
> To assign to a place of insignificance or of oblivion : put out of sight or mind
> To assign to an appropriate place or situation on the basis of classification or appraisal
> To place (generally a sports team) to a lower ranking division
Often, it is even used to mean delegate also though it is not considered to be apt usage. Both terms, is orignated from latin word legare, which means to send
Originally relegate meant to send into exile, banish and later it gained further meanings as mentioned above
She resigned when she was relegated to a desk job.
The football team was relegated from numero uno (first) position to fourth position due to their dismal performance during the season
If you don’t study well, you will be relegated to the lower class again.