1. combine or unite.   Hint First letter clue   2. increase toughness by gradual heat reduction.   First letter clue   3. grow bud or shoot.   First letter clue   4. build or invent.   First letter clue   5. break up or scatter.   First letter clue   6. seal seams to make watertight.   First letter clue   7. collect into a mass.   First letter clue