Will the orator be speechless if he lost it? (7,4)
I believe the answer is:
Here is my best explanation:
'will the orator be speechless' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'he lost it?' is the wordplay.
I cannot really see how this works, but
'he' could be 'bo' and 'bo' is found in the answer.
'it?' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is found in the answer.
This explanation may well be incorrect...
'if' is the link.
(Other definitions for address book that I've seen before include "list" and "List of contacts".)