Meaning of QUEEN OF SHEBA in English

Queen of She ‧ ba, the /ˌkwiːn əv ˈʃiːbə/ BrE AmE noun

1 . someone who is very rich or who spends money as if they were very rich, from a story in the Old Testament of the Bible about the wealth of the Queen of Sheba

2 . and I’m the Queen of Sheba humorous used as a reply when someone claims that they are famous or that they have done something impressive, but you do not believe them:

‘I’d like to reserve a table for tonight – this is Demi Moore.’ ‘Oh yeah, and I’m the Queen of Sheba.’

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.