Parvenu
Part of speech: adjective
Definition: Being a parvenu; also, like or having the characteristics of a parvenu.
Part of speech: noun
Definition: A person who has risen, climbed up, or has been promoted to a higher social class, especially through acquisition of wealth, rights, or political authority but has not gained social acceptance by those within that new class.
Upstart
Part of speech: noun
Definition: someone who has gained sudden wealth, power or influence, but has either not gained social acceptance or has become arrogant or presumptuous
Part of speech: adjective
Definition: self-important and presumptuous
Part of speech: verb
Definition: to rise suddenly, to spring