The term 'FIERY STACK' can be broken down into two words, 'FIERY' and 'STACK'. The word 'FIERY' is defined as something that is burning or glowing with intense heat or passion. The word 'STACK' is defined as a large, usually conical pile of hay, grain, or other material. Together, the term 'FIERY STACK' can be interpreted as a large pile of burning material. The crossword solution for this term is 'PYRE', which is defined as a heap of combustible material, especially one for burning a corpse as part of a funeral rite.