Syvar was a Vulcan Starfleet science officer in the later 24th century.
Syvar considered himself a highly skilled darts player. In 2371, while visiting Deep Space 9, he took the opportunity to play darts against the highly praised Chief Miles O'Brien with Quark, although Syvar did know that the Ferengi had not told Chief O'Brien about the game. Syvar offered Chief O'Brien the opportunity to withdraw without a loss of honor, but Chief O'Brien welcomed the challenge.
During the game, however, O'Brien injured his shoulder (right before what likely would have been the winning shot) and required immediate surgery. Syvar pointed out that by leaving, O'Brien would forfeit the game, but O'Brien left anyway. (DS9: "Shakaar")
Syvar was played by Sherman Howard.
Syvar was in several more scenes in early versions of the script, which were cut out. These would have revealed his approaching Chief O'Brien and his assignment aboard the USS Garuda. (Star Trek: Deep Space Nine Companion - A Series Guide and Script Library)