Related Clues:

• Open to change, adaptable - i.e. ball
• Liable to change rapidly and unpredictably
• Funny oval Scrabble piece that's changeable
• Liable to change unpredictably
• Liable to lead to sudden change
• The French having bad temper may become unstable
• Likely to blow up rodent about to turn tail
• Disposed to sudden changes
• Liable to sudden change
• Chemically unstable
• Likely to change
• Set off easily
• (Chemically) unstable
• Unusually evil lot, albeit at first apt to change
• Fickle; tending to vaporise