A person who has no chin, often has a larger forehead to make up for the 'lack of chin'
OH MY LOOK AT PAUL HOWKINS, HE'S SO CHINLESS
by IizKwl March 07, 2010
Someone who has down syndrome, due to them acting complete incompetent.
Ross Steineke is chinless, how the hell could he fuck that up.
by midnighte May 03, 2010