The word tsvi (צבי) is traditionally considered to mean "deer". For example, the Hebrew name "Tsvi" has the Yiddish equivalent "Hersh", and "Hirsch" means "deer" in German.
On the other hand, in Israel the word tsvi is used to mean "antelope", while deer are called eyal (איל). (At least, by people who deal with nature and animals.)
Why this discrepancy?