The IRW Makar was a Romulan warbird of the Tal Shiar, part of the joint fleet sent with the Obsidian Order against the Founders' homeworld in 2371 and destroyed in the Jem'Hadar ambush.
The Makar is named in the Deep Space Nine episode The Die Is Cast. Enabran Tain, former head of the Obsidian Order, leads a secret fleet of Romulan warbirds and Cardassian Keldon-class ships through the wormhole to wipe out the Founders by bombarding their planet in the Omarion Nebula.
The attack proves to be a trap. The planet is deserted, and 150 Jem'Hadar ships emerge from the nebula and tear the fleet apart. The Makar is among the first of the warbirds reported to have lost power and to be destroyed.
The battle all but eliminates both intelligence services, as the Founders had intended, and Garak and Odo escape only because the Defiant has followed them.