Is it possible to delete a tag after it has been created. For example when I post a question under the tag, Analytic number theory sometimes, Analytic only appears in the Tag column and the Analytic tag gets created. So if I want to delete the tag, how can I do it?
See these meta.SO questions:
- I accidentally created a tag. How do I delete it?
- How can we get rid of misspelled and unused (or “zombie”) tags?
As explained there, you simply remove the tag from all questions. Tags which are used for no questions are deleted automatically. This process runs once in 24 hours.
(Even tags having only 1 question can be removed automatically. This can happen if no other question have been added for 6 months. See, for example here for details and further links.)