verb

• (intransitive) To form an agreement or contract.
  "In return for the sovereign's protection, they compacted to police the content of public literature."

adj

• (archaic) Agreed, contracted.
  "O Gorice XI., most glorious King of Witchland, and O Lord Goldry Bluszco, captain of the hosts of Demonland, it is compact betwixt you, and made fast by mighty oaths whereof I, the Red Foliot, am keeper, that ye shall wrastle three falls together on these conditions, […]"

adj

• (of prose) Brief and pithy; not verbose.
  "a compact discourse"
• (topology, not comparable) Of a topological space:
• (topology, not comparable) Of a topological space:
• (obsolete) Joined or held together; leagued; confederated.
  "Thou fooliſh Frier, and thou pernicious woman / Compact with her that's gone:"

verb

• (transitive) To make more dense; to compress.
  "You need to excavate and remove the topsoil, line the subsoil with a geotextile, then lay and compact hardcore."