1. opal glass a milky white translucent or opaque glass
  2. middle class the social class between the lower and upper classes
  3. cover glass a small and very thin piece of glass used to cover the specimen on a microscope slide
  4. crown glass optical glass of low dispersion and low refractive index
  5. milk glass a milky white translucent or opaque glass
  6. bell glass a bell-shaped glass cover used to protect and display delicate objects or to cover scientific apparatus or to contain gases
  7. social class people having the same social, economic, or educational status
  8. age class people in the same age range
  9. soluble glass a viscous glass consisting of sodium silicate in solution
  10. highball glass a tall glass for serving highballs
  11. ground glass glass that diffuses light due to a rough surface produced by abrasion or etching
  12. middle-class occupying a socioeconomic position intermediate between those of the lower classes and the wealthy
  13. cheval glass a full length mirror mounted in a frame in which it can be tilted
  14. calculus the branch of mathematics that is concerned with limits and with the differentiation and integration of functions
  15. looking glass a mirror; usually a ladies' dressing mirror
  16. double-glaze provide with two sheets of glass
  17. googolplex a cardinal number represented as 1 followed by a googol of zeros (ten raised to the power of a googol)
  18. canaliculus a small canal or duct as in some bones and parts of plants
  19. goggle box an electronic device that receives television signals and displays them on a screen
  20. cut glass glass decorated by cutting or grinding facets