booklouse vs book louse

booklouse and book louse both are nouns.

Word	Noun	Adjective	Verb	Adverb
booklouse	Yes	No	No	No
book louse	Yes	No	No	No

As nouns, booklouse and book louse are synonyms defined as:

booklouse and book louse: minute wingless psocopterous insects injurious to books and papers

Other synonyms of booklouse include deathwatch, Liposcelis divinatorius.

booklouse (noun)	book louse (noun)
minute wingless psocopterous insects injurious to books and papers	minute wingless psocopterous insects injurious to books and papers