what does plenipotentiaries mean????

Answer 1

plenipotentiary
adj

1. Entrusted with, or conveying, full authority to act on behalf of one's government or other organization.

noun

plenipotentiaries
1. Someone, eg an ambassador, invested with such authority.

Etymology: 17c: from Latin plenus full + potentia power

Answer 2

That they've full power. They can do any act same as they were the person that in their State can do this.In general they're Ministers or Ambassadors and when they've the definition of
"plenipotentiary" they can sign any official act same as the signature was of the President,Prime Minister,etc.