leger vs account book

leger and account book both are nouns.

Word	Noun	Adjective	Verb	Adverb
leger	Yes	No	No	No
account book	Yes	No	No	No

As nouns, leger and account book are synonyms defined as:

leger and account book: a record in which commercial accounts are recorded

Other synonyms of leger include book, book of account, ledger.

leger (noun)	account book (noun)
a record in which commercial accounts are recorded	a record in which commercial accounts are recorded