to change something so that its shape, sound or appearance is different than normal
Many cult and extremist movements usually come about because someone distorts a doctrine.

in an irregular manner
I go visit the mall occasionally.

to stop someone from doing something
The bird prevents itself from being taken advantage of by cuckoos.

of an earlier time
We previously thought that it was not a good idea.

to act in response to something
It will react if we add another chemical.

to remain alive
He survived for twenty days on the small island.