1. unite by intertwining.   splice   initiate   impinge   invalidate   Hint Half-n-half Clue   2. increase in size or strength.   manipulate   precipitate   weather   wax   Half-n-half Clue   3. place one thing over another.   superimpose   ruminate   smelt   inhibit   Half-n-half Clue   4. harden into bone or become rigid.   smelt   postulate   regenerate   ossify   Half-n-half Clue   5. split into two opposite groups.   polarize   manipulate   vaporize   incorporate   Half-n-half Clue   6. burst inwards.   implode   secrete   regenerate   impinge   Half-n-half Clue   7. pierce or make hole(s) in.   incorporate   splice   perforate   pulverize   Half-n-half Clue