At and While

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

While and at are semantically related in part of speech topic. In some cases you can use "While" instead a conjunction "At", when it comes to topics like during.

While conjunction - At or during the time that.

At and while are semantically related in during topic. Sometimes you can use "At" instead a conjunction "While".