To cut or score; to wound superficially.
To prevent (something) from being successful.
The rain scotched his plans of going to the beach.
To debunk or discredit an idea or rumor.
The prime minister scotched rumors of his resignation.
To block a wheel or other round object.
The workers stopped the rig on an incline and scotched the wheels.
To dress (stone) with a pick or pointed instrument.
To beat yarn in order to break up slugs and align the threads.
Yarn is scotched immediately after it has been dried and while it is still warm. http//www.google.com/patents?id=DXdGAAAAEBAJ&pg=PP3&vq=scotched&dq=scotching
To clothe or cover up.
(Australian rhyming slang) To rape.