1. (of gas or air) of less density.   synthetic   synchronous   potable   rarefied   Hint Half-n-half Clue   2. with only one color.   saccharine   monochromatic   rarefied   viscid   Half-n-half Clue   3. pertaining to motion.   somatic   toxic   theoretical   kinetic   Half-n-half Clue   4. superfluous or excessive.   redundant   permeable   saline   seismic   Half-n-half Clue   5. short-sighted or lacking foresight.   noxious   static   seismic   myopic   Half-n-half Clue   6. marked with ridges or parallel grooves on surface.   quiescent   ligneous   striated   osseous   Half-n-half Clue   7. pertaining to heat.   thermal   quiescent   soluble   oblique   Half-n-half Clue