What is the greek word for science exhibition?

There isn't a single, perfect Greek word for "science exhibition." Greek doesn't have a single word that directly translates to the modern concept of a science exhibition, which is a relatively recent development.

However, you could construct a phrase using existing Greek words to convey the meaning. Here are a few options, depending on the nuance you want to emphasize:

* Έκθεση επιστημονική (Ékthesis epistimonikí): This is a straightforward translation using "exhibition" (έκθεση - ékthesis) and "scientific" (επιστημονική - epistimonikí). It's accurate and easily understood.

* Δείγμα επιστημονικής έρευνας (Dígma epistimonikís éreynas): This translates to "sample of scientific research," which might be a suitable description depending on the content of the exhibition.

* Παρουσίαση επιστημονικών επιτευγμάτων (Parousíasi epistimonikón epitygmátōn): This means "presentation of scientific achievements," focusing on the accomplishments showcased.

The best choice depends on the context. The first option, Έκθεση επιστημονική, is the most generally applicable and easily understood.