At and Next

At noun - A highly unstable radioactive element (the heaviest of the halogen series); a decay product of uranium and thorium.

Next and at are semantically related. In some cases you can use "Next" instead an adverb "At".

Next adverb - At the time or occasion immediately following.

At and next are semantically related. Sometimes you can use "At" instead the word "Next" as an adverb or a preposition.