A splum is the metal grommet or fabric eyelets that are often sewn or attached near the top of each of the six sections of fabric of a baseball cap to provide ventilation.
The splum of my baseball cap feels like it dented my brain when I hit my head on the low ceiling.
by armyjackson December 30, 2011
A semi combonation of splooge and cum. It is a weak ejaculation do to physical status or poor sperm count. A weaker built person may splum verus a more in shape and heathy person who would climax normally.
The meager AV nerd splum as the cheerleader kissed his nutsack.
by Klusky March 28, 2005