A (usually annual) gathering of old, stinky, unwashed, and severely overweight men (with a limited number of women, usually of the same qualities) where antiquated and largely useless radio equipment is bought, sold, and traded, usually at exorbitantly high prices.
While some hamfests are useful for finding odd parts and rare equipment, many have degraded in quality over the years and are not worth going to any more.
I was at this one hamfest
in Bowie, MD and this hambone
picked up a simplex repeater
and said, "Duh, so it records the radio, TTX?"
h4mb0n3-1: Man, did you go to the Vienna hamfest this year, the one at NOVA?
h4mb0n3-2: No way, d00d, that hamfest is not as good as it used to be.