Communication between two or more minds.
The sender may project a certain thought to another, which may be interpreted in a number of ways (color, number, letter, words, etc) by the reciever.
Telepathy is used by the supposed "Wingmakers" to keep in contact with one another.
The ability to synchronise the informational processes within one's mind to those of another individual; or conversely, to sychronise the informational processes of another's mind to one's own. This manifests as a form of direct mind-to-mind communication, without any medium of transmission involving energy and matter. See psionics
Telepathy can only be achieved when an individual has understood the principles of psionics
is the transmission of information from one person to another without using any of our known sensory channels or physical interaction
I can hear a friend 2.2 km away using telepathy.