My concise working definition of intuition:
Intuition is an innate mental ability in human beings, which functions as a normal biological sensory system receiving and transmitting information through its unique effects, classified as 'psi effects'; it is an adaptive process evolving naturally over time as an extremely useful, efficient defense mechanism.
An expanded general description:
To begin adopting intuition as your own ability, start by equating it your other very familiar sensory systems, e.g., your vision, hearing and taste, to name a few. Like these, in fact like all the well-known human senses, intuition, functioning as a common sensory system, also provides helpful information to keep you out of harm’s way and ‘on track’ while you move around in daily life.
You can discover how to recognize its unique spontaneous signals – called psi-effects - and with training, learn to control it when you would like to use it and benefit from its information.