An illness that causes someone to believe that they are a large trout, and therefore engage in large trout-related activities, such as swimming up waterfalls and spawning. Large Trout Syndrome can be contracted via contact with fairly small trout that wish they were larger.
Friend: I like your shirt, Craig.
Craig: GLUG GLUG GLRBBSHHH GLUUUUH
Friend: Uh, oh, Craig, you've caught Large Trout Syndrome!
Craig: GLRSHHHHH GLUG GLRSHH GLUUURG
Craig: GLUG GLUG GLRBBSHHH GLUUUUH
Friend: Uh, oh, Craig, you've caught Large Trout Syndrome!
Craig: GLRSHHHHH GLUG GLRSHH GLUUURG
by Admiral Foxface December 2, 2019

A mouth that is small and shallow on the inside but the lips and very front of the mouth can open wide.
by amileynjamez November 3, 2020

by Diabetic kev January 4, 2019

Dude: "Hey Jerry, I hit the shitter earlier, and unleashed brown trouts!"
Jerry: "YOOhohooooww!! Out came the brown trouts!!!111!!11!"
Dude: "what the fuck?"
Jerry: "OOohhohhoo! I got a nice waft of that poo stench!! Yipeee!"
Jerry: "YOOhohooooww!! Out came the brown trouts!!!111!!11!"
Dude: "what the fuck?"
Jerry: "OOohhohhoo! I got a nice waft of that poo stench!! Yipeee!"
by Mountaineer007251 March 25, 2022

by Purple_haze420 January 8, 2023

by Search it up then March 1, 2024

by Trout mouth February 14, 2022
