adj

• (with infinitive) Obliged (to).
  "You are not legally bound to reply."
• (linguistics, of a morpheme) That cannot stand alone as a free word.
• (mathematics, logic, of a variable) Constrained by a quantifier.
• (dated) Constipated; costive.

adj

• (obsolete) Ready, prepared.
  "This certain,—that a band of war / Has for two days been ready boune, / At prompt command to march from Doune […]."
• (with infinitive) Very likely (to), certain to
  "They were bound to come into conflict eventually."

noun

• (often used in plural) A boundary, the border which one must cross in order to enter or leave a territory.
  "I reached the northern bound of my property, took a deep breath and walked on."
• (mathematics) A value which is known to be greater or smaller than a given set of values.

verb

• (transitive) To surround a territory or other geographical entity; to form the boundary of.
  "France, Portugal, Gibraltar and Andorra bound Spain."
• (transitive, mathematics) To be the bound of.