1an invitation to return for a second audition or interview:he was one of only twelve applicants to receive a callback
2a telephone call made to return one that someone has received.
3 [mass noun] a security feature used by some computer systems accessed by telephone, in which a user must log on from a previously registered phone number, to which the system then places a return call.
callback in other Oxford dictionaries
Definition of callback in the US English dictionary
