A man's penis, specifically in the erect position.
My mantenna is detecting some estrogen in the area, so I should follow it to find the girl of my dreams.
by Marcus Solomon October 31, 2007
the male penis... but unlike many antennas, this mantenna can only be used properly by a female... unless your gay.
"Oooo... look at the mantenna go up!"
by D&J November 16, 2002
Another word for male genitalia. Synonymous with Wang, Wiener, Cock, Dick, Junk, and any other word for Penis.
Guy 1:"So, hows reception on the old mantenna?"

Guy 2:"Reception on the the wha?"
by Khazilla November 24, 2010