To go mad, crazy, stop thinking right, or to lose your mind
“Mum said I lost the plot, at least I never lost my crop”
Acting out of character.
Behaving abnormal, weird or crazy.
She just sits there, staring at the walls. I think she has lost the plot
Dad completely lost the plot when he saw my picture on the front of the porno DVD.
When you’re doing the ultimate nasty and the receiving partner enters a blissful state of confusion
“Last night I was giving it to Priscilla so hard she lost the plot, couldn’t even remember her name.
Slang for when someone loses there focus or ends up failing to do what the had set out to do.
When I failed my chemistry test, I had lost the plot.
I was telling my friend a funny story, but then I lost the plot and started talking about my grandmother’s brownie recipe.