Select the most appropriate meaning of the given idiom.

Red letter day

Memorable day

The most appropriate meaning of the idiom "red letter day" is memorable day.

This idiom is used to describe a day that is considered to be special or important. It is often used to describe a day that is a holiday, a birthday, or a day on which something significant happened. For example, you might say "Today is a red letter day for me. It's my wedding anniversary." This means that your wedding anniversary is a day that you will always remember.

The other options are not as accurate descriptions of the meaning of the idiom.

• Rose day: This is a day celebrated by couples on February 7 as a token of love and affection.
• Holiday: This is a day on which people do not have to work or go to school.
• Birthday: This is the anniversary of the day on which someone was born.