Meantime and While

Meantime noun - The time between one event, process, or period and another.

While and meantime are semantically related in in the intervening time topic. In some cases you can use "While" instead the word "Meantime" as an adverb or a noun.

While noun - An indefinite but usually short period of time.

Meantime and while are semantically related in time interval topic. You can use "Meantime" instead the word "While" as a noun or an adverb.