Slip (one's) trolley verb phrase slang
To go crazy; to become angry
My mother slipped her trolley when she knew that I had stayed out past curfew.
I'm sure my parents will slip their trolley after I messed up their car.
If my parents notice this dent in the car, they will be slipping their trolley.
Stupid or crazy
To argue with somebody
If you're off your trolley, your ideas or behaviour are crazy or insane.
The verb "slip" must be conjugated according to its tense.
The origin of this slang is not clear.