A Samarian sunset is a beverage.
In 2265, Montgomery Scott told visitors at Drozana Station that Cassidy liked Samarian sunset for its sour taste but was unhappy that the drink was so weak. She had been trying to convince Drozana's bartender to add garnish to prolong the happy feeling but he wouldn't because then it wouldn't be a Samarian sunset. (STO mission: "Night of the Comet")
Quark served Samarian sunsets in his bar on Deep Space 9. Natima Lang enjoyed the Samarian sunsets that Quark prepared for her, although she stopped drinking them after their relationship ended. (DS9 episode: "Profit and Loss", DS9 - Mission Gamma novel: This Gray Spirit, ST - Terok Nor novel: Dawn of the Eagles)