Any species of the class Hexactinellida of sponges, which have a skeleton made of four- and/or six-pointed siliceous spicules.

A glass or phial, shaped like an inverted funnel, with a very thin convex bottom that can be made concave or convex by sucking out or blowing in air.

A small glass for alcoholic drinks. / (Australia) A quarter-pint glass (formerly 5 imperial fl oz, metrized to 140 ml).

sheet glass; a type of glass, initially produced in plane form, commonly used for windows, windshields, etc.

A drinking glass with hidden holes that spill the drink when tilted, used as a prank.

(historical) The psychological/psychiatric delusion that one is made of glass and will shatter if one sits on a hard surface or is struck.

(vehicles) the small triangular-shaped side window on some vehicles.

(obsolete) A glass that displays objects; a mirror.

(archaic, medicine) A glass vessel used in cupping.

A kind of early telescope. / (historical) An instrument for viewing an enlarged image of engraved prints or maps http://www.monticello.org/site/research-and-collections/perspective-glass.