American English | British English | Meaning
------- | -------- | --------
color | colour | The property of an object that results from the way it reflects light.
center | centre | The middle point of something.
analyze | analyse | To examine something carefully.
defense | defence | The act of protecting something from attack.
judgment | judgement | The ability to make wise decisions.
realize | realise | To become aware of something.
theater | theatre | A building where plays are performed.
practice | practise | To do something repeatedly to improve a skill.
program | programme | A plan of events or actions.
tire | tyre | A rubber covering for a wheel.
catalog | catalogue | A list of items.
canceled | cancelled | To stop something from happening.
favor | favour | A kind act.
aging | ageing | The process of getting older.
enroll | enrol | To sign up for something.
traveler | traveller | A person who travels.
neighbor | neighbour | A person who lives nearby.
acknowledgment | acknowledgement | The act of recognizing something.
license | licence | A permit that gives permission to do something.
Note: These are just a few examples, and there are many other words with different spellings in American and British English.