zaatar means: A mixture of sumac and sesame seed. This herb mixture is also available in prepared form at many Middle Eastern grocery stores. There are many factors that can affect the quality of zaatar. (in Cooking Dictionary)
What else does zaatar mean?
Mixture of Middle Eastern herbs and spices, typically including thyme, marjoram, oregano, sumac and sesame seed, as well as salt and other ingredients. (in Merlin Dictionary)