Used to describe someone who seeks to rise in social status.
El arribista siempre busca la oportunidad de codearse con personas influyentes para avanzar en su carrera.
The upstart is always looking for the opportunity to rub shoulders with influential people to advance his career.
El arribista que se sentó a mi lado solo hablaba de sus conexiones.
The upstart sitting next to me only talked about his connections.