Upādāna means clinging, and also fuel. In the twelve links of dependent origination it follows craving and conditions becoming. The Buddha spoke of the five aggregates as the five aggregates of clinging, the fuel by which the fire of existence burns; nibbāna is that fire going out.
Upādāna
Clinging or grasping: the intensified craving that binds beings to becoming.
Also: Upadana, clinging