1. drug or treatment preventing infection.   fissure   dissection   gyroscope   antiseptic   Hint Half-n-half Clue   2. tooth of a wheel.   emetic   contagion   cog   delirium   Half-n-half Clue   3. wasting away.   emetic   atrophy   diminution   delta   Half-n-half Clue   4. purging of passage of body; outlet to emotion.   catharsis   clavicle   astigmatism   antiseptic   Half-n-half Clue   5. compulsion or repression.   decomposition   constraint   extrapolation   equinox   Half-n-half Clue   6. ability to produce desired effect.   converse   efficacy   catharsis   cistern   Half-n-half Clue   7. sharp-edged tool used for cutting.   chisel   balm   autopsy   consistency   Half-n-half Clue