A person who intentionally instigates, incites, or starts something, especially one that creates trouble.

A flat, (usually) vertical surface onto which controls, instruments, and displays are mounted.

(aviation) A collection of radio navigation aids (always including a localizer and glideslope, and often one to three marker beacons as well) used by pilots for approach guidance to a specific airport runway, especially when visibility is limited.

The velocity of an object at any given instant (especially that of an accelerating object).

(communication, computing) A message conveyed through an instant messaging program.

(communication, computing) To convey a message via an instant messaging program.

A coin or other item of currency.

Innately; by instinct; without being taught.

The tendency of an organism to revert to instinctive behaviors that can interfere with the conditioned response.

One of a series of parts, whether equal or unequal to the other parts of the series, of a given entity or a given process, which part presents or is presented at a particular scheduled interval.