I understand what ROC graphs are but not why they have that name. 
Could you tell me what the name means?

Thank you.

The odd name stems from its original development within the field of
signal detection theory.  It was a formalism first used to
characterize how well a receiver is able to detect a signal in the
presence of noise.

Thank you so much, deeptimer.

Well, the origin of the name, although coming from the signal
detection theory is an acronym of Receiver Operating Characteristic. 
I think thats what you wanted to know.

Deezeal, I did know that (see Subject), but thank you.