quite similar in practice to Arabian Goggles, the Norman Helmet involves placing one's testicles over another's eyes while the reciever is on his/her back (usually asleep), and the shaft of the penis runs down the length of the receiver's nose, reminiscent of an medieval cranial protection device from the days of yore.
"Jimmy fell asleep first at the sleepover, and so billy gave him a Norman Helmet"
or
"right before i came on yo momma's face, i gave that bitch a phat Norman Helmet"
or
"right before i came on yo momma's face, i gave that bitch a phat Norman Helmet"
by alex el maestro October 24, 2006
When ones lady friend lays down on her back, One then proceeds to place ones testicles on her forehead and cock down over her nose thus resembling a Norman war helmet!
by The peoples poet RP August 16, 2011