Correct spelling, explanation: the word cancelled is past simple and past participle form, as well as an adjective participle of the verb to cancel. It was created by adding the most common suffix (-ed) to the root. As you can see, cancel is a regular verb, which means that its conjugation is easy to remember. If you’re using American English, you can spell it as canceled as well. Cancelled is a more popular form in British English.

Definition of cancelled:
1. verb (past simple, past participle), to decide that something arranged in advance will not happen, or to state that you do not wish to receive something
The company cancelled the launch of its new product after discovering a critical flaw during final testing.
The airline cancelled my flight without providing any explanation, leaving me stranded at the airport.
2. adjective participle, to call off or postpone indefinitely
The concert was cancelled due to the heavy thunderstorm, disappointing many eager fans.
The event was cancelled at the last minute due to low attendance, resulting in disappointment for the organizers and attendees alike.

Collocations with cancelled:
Some most commonly used collocations include:
1. Cancelled flight: when a scheduled flight is terminated before it takes off, usually due to various reasons like bad weather or operational issues.
The airline had to apologize to the passengers for the cancelled flight due to a mechanical issue.
2. Cancelled event: refers to an occasion, gathering, or happening that is called off or not held as planned.
The outdoor concert was cancelled because of the heavy rain forecast.
3. Cancelled plans: when arrangements or scheduled activities are abandoned or terminated.
We had to make new arrangements after our weekend camping trip was cancelled at the last minute.
4. Cancelled appointment: when a scheduled meeting with a professional, such as a doctor or dentist, is called off or rescheduled.
The doctor’s office charged a fee for the cancelled appointment made less than 24 hours in advance.

Correct spelling, explanation: both cancelled and canceled are correct spellings of the same word, and which one you should use depends on the variety of English you are using. In American English, it is more common to use canceled with one -l. In British English and some other varieties of English, cancelled with two -ls is the preferred spelling. The most important thing here is consistency.