When a male's junk is highlighted by his pants, either purposely or without intention. It often happens when a dude is particularly well endowed and/or is wearing a slimmer cut pant that accentuates the crotchal region. Similar to a pants tent but not an illusion and not necessarily indicative of excitement.
Lance was an average dude but his new jeans had a Hammaconda Effect, making him look particularly well endowed.
by Zstreich April 03, 2013