What is an antonym for but?

There isn't a single perfect antonym for "but" because its meaning depends on the context. Here are some options depending on the situation:

If "but" means "except":

* And

* Also

* Furthermore

* In addition

If "but" means "however" or "on the other hand":

* Therefore

* So

* Consequently

* Accordingly

* Thus

If "but" means "yet":

* Still

* Nevertheless

* Nonetheless

* Despite that

If "but" is used in a negative context:

* Therefore

* So

* Consequently

* Hence

To find the best antonym, consider the specific meaning of "but" in your sentence and choose the word that best conveys the opposite idea.