$.wait(group, deferred ,callback)

Description: Wait for a deferred object to resolve (jQuery, jQuery.Deferred, deferred jQuery chain, …) in a named thread group.

group – string, optional
a name of the thread group that this waiting should be assigned to.
Defaults to the empty string ''.
deferred – any object with .promise()
e.g. a jQuery selection, a jQuery.Deferred, or another deferred jQuery chain.
callback – function(), optional
a method that is called once just before continuing the invocation chain.

The static $.unwait() allows to break wait states defined this way.