In Sri Lanka and India, jaggery is a thick, dark brown syrup obtained by boiling down the sugarcane sap, thus concentrating the sugar.
From the site of Dhampur Invertos Ltd.:
Dhampur's Jaggery is actually Indian turbinado. The sweet sap from the sugarcane is boiled with constant stirring steadily to a thickened syrup. India's epic narrative Mahabharata depicts how jaggery was used in sophisticated sweets at the time of Lord Krishna's appearance 5,000 years ago.
In Sri Lanka, jaggery is used to sweeten buffalo milk curd - the combination is rather delicious.
Jaggery appears to have some relation with turbinado, which is a rather cool word.