οπτιμιστής
From LSJ
μεριμνᾷς καὶ τυρβάζῃ περὶ πολλά → you are worried and bothered about so many things, thou art careful and troubled about many things, you are worried and upset about many things
Greek Monolingual
ο, θηλ. -ίστρια
1. οπαδός του οπτιμισμού
2. αισιόδοξος. [ΕΤΥΜΟΛ. < γαλλ. optimiste < λατ. optimum «άριστο» + -iste].