noun

• (countable, uncountable, metallurgy) A solid metal object with uniform (round, square, hexagonal, octagonal or rectangular) cross-section; in the US its smallest dimension is ¹⁄₄ inch or greater, a piece of thinner material being called a strip.
  "Ancient Sparta used iron bars instead of handy coins in more valuable alloy, to physically discourage the use of money."
• (typography) Any of various lines used as punctuation or diacritics, such as the pipe ⟨|⟩, fraction bar (as in 12), and strikethrough (as in Ⱥ), formerly (obsolete) including oblique marks such as the slash.
• (mathematics) The sign indicating that the characteristic of a logarithm is negative, conventionally placed above the digit(s) to show that it applies to the characteristic only and not to the mantissa.
• (physics) A similar sign indicating that the charge on a particle is the negative of its usual value (and that consequently the particle is in fact an antiparticle).

verb

• (transitive) To obstruct the passage of (someone or something).
  "Our way was barred by a huge rockfall."
• (transitive) To prohibit.
  "I couldn't get into the nightclub because I had been barred."
• (transitive) To lock or bolt with a bar.
  "to bar the door"

prep

• (horse racing) Denotes the minimum odds offered on other horses not mentioned by name.
  "Leg At Each Corner is at 3/1, Lost My Shirt 5/1, and it's 10/1 bar."

name

• (legal senses) Alternative spelling of bar.