Identify the common category: Items (1), (2), (4), and (5) are all names of national currencies.
\begin{itemize}
\item Lek — currency of Albania.
\item Zloty — currency of Poland.
\item Drachma — historical currency of Greece (pre-euro).
\item Real — currency of Brazil.
\end{itemize}
Contrast with option (3): Diner (spelled with an e) is not a currency; it is an English word meaning a person who dines or a type of casual restaurant. (A currency spelled Dinar would fit the pattern, but that is not what is written.)
Therefore, the only item not belonging to the currency category is (3) Diner.
\[
\boxed{\text{Odd word: (3) Diner}}
\]