Subject to change' is an expression that is used to indicate that something is not fixed and can be altered. The crossword solutions for this term are FLUID (5 letters), MUTABLE (7 letters), REACTIVE (8 letters), IFFY (4 letters), MUTATORY (8 letters), and INDOUBT (7 letters). FLUID refers to something that is able to flow freely and easily change shape. MUTABLE means capable of being changed or adapted. REACTIVE describes something that responds quickly to a stimulus. IFFY is an informal term for uncertain or questionable. MUTATORY is another word for changeable. Finally, INDOUBT is a synonym for uncertain.