To replace is to find a substitute for something, to put something back where you got it from, or to take the place of something.
(verb)
- When you take the milk from the shelf and then you put it back, this is an example of a time when you replace the milk where you found it.
- When you throw out your old shoes and get new ones, this is an example of a time when you replace your old shoes.
- When new shoes take the place of your old ones, this is an example of a time when the new shoes replace the old.