Hebdomadal is an adjective that means occurring every week.

The Greek word Hepta (HEPT ah) means seven. So when our word of the day drifted into English, it came to refer to a period of seven days that we call a week. A hebdomadal activity is something that takes place weekly. For example: Our hebdomadal meetings are a very helpful way to get things in order. That’s why I recommended weekly meetings in the first place.