A pre-shared key identifies a communicating party during a phase 1 IKE negotiation. It is called "pre -shared" because you have to share it with another party before you can communicate with them over a secure connection.
A shared secret key passed to both parties in a communication flow, using an unspecified manual or out-of-band mechanism.
a shared, secret key that uses IKE for authentication
An authentication technology used by IPSec. Pre-shared means the parties must agree on a shared, secret key that becomes part of the IPSec policy. Information is encrypted before transmission using the shared key, and decrypted on the receiving end using the same key. If the receiver can decrypt the information, identities are considered authenticated.
TKIP passphrase used to protect your network traffic in WPA. Some manufacturers use the term " pre-shared secret" instead.
A pre-shared key or PSK is a secret which was previously shared between the two parties using some secure channel before it needs to be used. Such systems almost always use symmetric key cryptographic algorithms. The characteristics of this secret or key are determined by the system which uses it; some system designs require that such keys be in a particular format.