1. senior class final grade or class in high school or college
  2. junior class penultimate class in high school or college
  3. superclass (biology) a taxonomic class below a phylum and above a class
  4. sandglass timepiece in which the passage of time is indicated by the flow of sand from one transparent container to another through a narrow passage
  5. sunglass a convex lens that focuses the rays of the sun
  6. second class not the highest quality in a classification
  7. second-class of inferior status or quality
  8. underclass the social class lowest in the social hierarchy
  9. social class people having the same social, economic, or educational status
  10. snorkel device allowing a swimmer to breathe while face down
  11. Senna auriculata evergreen Indian shrub with vivid yellow flowers whose bark is used in tanning; sometimes placed in genus Cassia
  12. sophomore class the second class in a four-year college or high school
  13. Synercus Cape buffalo
  14. master class a class given to talented students by an expert
  15. schnorchel air passage provided by a retractable device containing intake and exhaust pipes; permits a submarine to stay submerged for extended periods of time
  16. schnorkel air passage provided by a retractable device containing intake and exhaust pipes; permits a submarine to stay submerged for extended periods of time
  17. upper class the class occupying the highest position in the social hierarchy
  18. lower class the social class lowest in the social hierarchy
  19. snorkeling skin diving with a snorkel
  20. upper-class occupying the highest socioeconomic position in a society