I'm commenting because I am the bearer of the name Amandus. It is my middle name and it's been passed down 3 generations- my grandfather had it, my father, and now me. I'm happy to have so a rare name that dates very far back into history.
In the description, it calls Amandus a derivitive of amanda, and under the description of amanda it says it comes from Amandus. Amandus I believe is the original as its history can be traced back 10 centuries more than amanda could be according to the descriptions.
Oh, awesome, first comment! Stating the obvious here, but the name Amanda is a feminine derivative of this name. :) This is my big sister's name, Amanda. She always wondered what the male equivalent to her name was, haha.