1. layer of earth's crust or society.   indices   perimeter   stratum   quadruped   Hint Half-n-half Clue   2. sleeplessness.   psychosis   insomnia   objective   repulsion   Half-n-half Clue   3. increase.   pigment   torque   increment   penumbra   Half-n-half Clue   4. passing from one state to another.   propellant   plasticity   transition   mirage   Half-n-half Clue   5. stone to test gold alloys; criterion.   satellite   touchstone   serendipity   perigee   Half-n-half Clue   6. path followed by body under forces.   solvent   precipitant   trajectory   quagmire   Half-n-half Clue   7. violent disturbance or agitation.   vertex   yield   respiration   turbulence   Half-n-half Clue