noun

• (figurative) Something that creates a division, gap or distance between things.
  "It is one of the ironies of capital cities that each acts as a symbol of its nation, and yet few are even remotely representative of it. London has always set itself apart from the rest of Britain — but political, economic and social trends are conspiring to drive that wedge deeper."
• (geometry) A five-sided polyhedron with a rectangular base, two rectangular or trapezoidal sides meeting in an edge, and two triangular ends.
• (architecture) A voussoir, one of the wedge-shaped blocks forming an arch or vault.
• (archaic) A flank of cavalry acting to split some portion of an opposing army, charging in an inverted V formation.

verb

• (transitive) To support or secure using a wedge.
  "I wedged open the window with a screwdriver."
• (ambitransitive) To force into a narrow gap.
  "He had wedged the package between the wall and the back of the sofa."
• (transitive) To pack (people or animals) together tightly into a mass.
• (transitive) To work wet clay by cutting or kneading for the purpose of homogenizing the mass and expelling air bubbles.

noun

• (UK, Cambridge University slang) The person whose name stands lowest on the list of the classical tripos.
  "The last man is called the Wedge, corresponding to the Spoon in Mathematics."