This is the 4945th most frequent Japanese word.
祝
"祝" means "to celebrate" or "congratulations."
In this sentence, '祝' is used as part of the verb '祝おう' (let's celebrate), derived from '祝う' (to celebrate). It involves expressing joy or happiness for an occasion.
彼の誕生日を祝おう。
Let's celebrate his birthday.
Here, '祝' is used in the noun '祝賀会' (celebratory event), referring to a formal occasion dedicated to celebrating something.
祝賀会が盛大に行われました。
The celebratory event was held with grandeur.
In this instance, '祝' appears in 'お祝い' (congratulations), denoting a means of expressing or acknowledging happiness or goodwill towards another person.