adj

• (of cattle) Unbranded.
  "Occasionally some young men who have no cattle of their own will take part in these expeditions, or they will give their services by the year to receive a pro rata of all the maverick cattle that may be found. [Quoted from The Texas New Yorker, pages 110–111.]"

noun

• (by extension) Anything dishonestly obtained.
• (by extension) One who is unconventional or does not abide by rules.
  "Among historians he was a maverick because of his belief that history is meaningless."
• (by extension) One who creates or uses controversial or unconventional ideas or practices.
  "We then drift back into our old habits, glorify efficiency, and smile knowingly at the mavericks within the faculty who want the administration to take democracy seriously."
• (military) A person in the military who became an officer by going to college while on active duty as an enlisted person.
  "They had been working for and with each other for a very long period and their tolerance for “mavericks” was very high, especially if these mavericks continued to get promoted."

verb

• (US) To take an unbranded range animal.
  "The court permitted the State to prove, over defendant's objections, that Thedford met Noon Tucker and Calvery driving the yearling over to Bachelor's for delivery. Thedford inquired of Noon "if that [meaning the yearling] was one he had mavericked?""
• (by extension) To seize without a legal claim.