If you mean "tag" as a label:
* Entfernen: This means "to remove" and can be used for taking off a label.
* Ablösen: This means "to peel off" or "to detach" and could be used for removing a sticky label.
* Lösen: This means "to loosen" or "to release" and might work for a label that is attached with a string or clip.
If you mean "tag" as in "to tag someone" (like in a game):
* Entkommen: This means "to escape" or "to get away" and could be used for avoiding being tagged.
* Ausweichen: This means "to dodge" or "to evade" and works for dodging a tag attempt.
If you mean "tag" as in "to label something" (like with a hashtag):
* Entfernen: This means "to remove" and could be used to remove a hashtag from a post.
* Löschen: This means "to delete" and could be used to remove a hashtag.
It's important to consider the specific context of the situation to choose the best opposite for "tag" in German.