A Rossism is an error in speech in which a figure of speech or sentence is jumbled or confused, yet still intelligible.
It was named after Ross O'Donovan, part of the Let's Play duo Steam Train, which is a spin-off of another Let's Play series called Game Grumps. Ross is well-known for accidentally jumbling up locutions.
Some examples for Rossisms:
"That train has sailed."
"It's like listening to a mirror."
"Don't count your chickens before they egg"
"How you going?"
"is rly good"
The greatest man ever to live. Never made a mistake only made happy accidents. Loved Happy Little Trees and Happy Little Clouds, son was just as good at painting as him but just did not have the soft voice that tickles all our buttholes, may he rest in power as the greatest human ever to live