It's when you go into freazing water and you dick shrivels up...
John and I went to the river and it was so cold i got river dick...
The term for a small penis/crotch. The term originate's from a male leaving the sea in his Y-front's and having a small crotch. The term can be used to describe someone whou you feel has a small penis but act's as if he has a large one. The "river" part of the word can be transferred to other word's for the same small effect.
Sunbather 1 - "Hey look at that guy, he's wearing tighty whitey's that are obviously a size too small."
Sunbather 2 - "I know, it would be more bearable but he as such a riverdick."
Person 1 - "Look at that guy acting like he's all that."
Person 2 - "I know, i bet he's got a right riverdick!"
Person 1 - "These shoe's don't fit."
Person 2 - "Are they rivershoe's?"
a term refering to the stench of ones dick after being in a body of water, such as a river.
Girl: Hey whys that smell so funny?
Guy: No worries, just a case of the river dick. Ill go shower if you want..
Girl: Na i kinda like it...
Guy: Well - ok then...continue.