bore
n. countable B1 Intermediate US //ˈbɔɹ// UK //bˈɔː// bore
n. someone or something that is not interesting at all. You use this to describe a person who talks too much about dull things or a situation that makes you feel tired of waiting.
n. a person or situation that is perceived as tedious, dull, or uninteresting. Often used in social contexts to describe individuals who lack engaging conversational skills.
The long meeting was such a bore.
I tried to be polite, but my neighbor is such a bore when he starts talking about his stamp collection.
Despite the host's efforts to liven up the evening, the guest of honor proved to be a complete bore, recounting every detail of his commute.
Usage
Commonly used with the intensifier 'such a' to emphasize the degree of dullness.