1. abstract   distinct or unconnected.   theoretical and not concrete.   boiling or enthusiastic.   existing from birth.   Hint Half-n-half Clue   2. impermeable   of exterior curvature or bulging outwards.   heat-liberating.   impervious or unpassable.   having common center.   Half-n-half Clue   3. centrifugal   based on hypotheses or assumptions.   flying or radiating from a center.   produced by fire or volcanic action.   not able to penetrate or understand.   Half-n-half Clue   4. calorific   heat-liberating.   infinitely small or very tiny.   of interior curvature or hollow.   shaped like an oval; ambiguous or baffling.   Half-n-half Clue   5. eccentric   not concentric or odd.   unavoidable or bound to occur.   diverse or mixed.   sharply pungent.   Half-n-half Clue   6. biennial   two-year long or every two years.   impenetrable or unpassable.   causing compression or contraction.   secure or resistant to.   Half-n-half Clue   7. anthropoid   confirmed or recurring as a disease.   not conventional.   resembling man or man-like.   secure or resistant to.   Half-n-half Clue