noun

• The way in which a mechanical device acts when used; especially a firearm.
  "pump-action shotgun"
• (music) The mechanism, that is the set of moving mechanical parts, of a keyboard instrument, like a piano, which transfers the motion of the key to the sound-making device.
  "The run in bar 12 is almost impossible with this piano's heavy action."
• (music, lutherie) The distance separating the strings and the fingerboard on a string instrument.
  "You're getting fret buzz because the action is too low."
• (slang, typically with a quantifier) Sexual intercourse.
  "She gave him some action."

adj

• (Manglish) arrogant

verb

• (transitive, management) To act on a request etc, in order to put it into effect.
  "‘Here, give me the minutes of Monday’s meeting. I’ll action your points for you while you get on and sort out the open day.’"
• (transitive, chiefly archaic) To initiate a legal action against someone.
  "‘I have no business to settle with you—arrest me, Sir, at your peril and I’ll action you in law for false imprisonment.’"