birthday
[C] Countable
pl: birthdays
This term carries a strong emotional weight of celebration, renewal, and personal milestone. It is almost always associated with positive social rituals, such as gifting, cake, and gatherings, making it a focal point of familial and social bonding. In a broader cultural sense, the word can be used to describe the origin or founding date of an organization or a conceptual idea, though it retains the celebratory tone of a personal anniversary even in professional or historical contexts.
Countable because it refers to a specific recurring annual event that can be counted over a lifetime.