telephone book vs phone book

telephone book and phone book both are nouns.

Word	Noun	Adjective	Verb	Adverb
telephone book	Yes	No	No	No
phone book	Yes	No	No	No

As nouns, telephone book and phone book are synonyms defined as:

telephone book and phone book: a directory containing an alphabetical list of telephone subscribers and their telephone numbers

Other synonyms of telephone book include phonebook, telephone directory.

telephone book (noun)	phone book (noun)
a directory containing an alphabetical list of telephone subscribers and their telephone numbers	a directory containing an alphabetical list of telephone subscribers and their telephone numbers