1. harmless substance given as dummy medicine.   placebo   quagmire   satellite   psychosis   Hint Half-n-half Clue   2. outer boundary for closed figure.   strut   perimeter   orifice   kaleidoscope   Half-n-half Clue   3. tendency to drive back or distaste.   symmetry   repulsion   orifice   projectile   Half-n-half Clue   4. breathing.   prototype   respiration   marsupial   solvent   Half-n-half Clue   5. substance or liquid that dissolves solute.   solvent   log   nutrient   synthesis   Half-n-half Clue   6. substance that causes solid matter in solution to deposit.   precipitant   spatula   suture   uniformity   Half-n-half Clue   7. observed fact or occurrence subject to scientific study.   phenomenon   indices   perimeter   increment   Half-n-half Clue