What is the meaning of upper?

noun

• The higher of two berths.
  • synonyms: upper berth
• Piece of leather or synthetic material that forms the part of a shoe or boot above the sole that encases the foot.
  • usage: "Uppers come in many styles"
• A central nervous system stimulant that increases energy and decreases appetite; used to treat narcolepsy and some forms of depression.
  • synonyms: amphetamine, pep pill, speed

adjective

• The topmost one of two.
• Higher in place or position.
  • usage: "the upper bunk"; "in the upper center of the picture"; "the upper stories"
• Superior in rank or accomplishment.
  • usage: "the upper half of the class"