book vs accumulation

book and accumulation both are nouns.

Word	Noun	Adjective	Verb	Adverb
book	Yes	No	Yes	No
accumulation	Yes	No	No	No

As nouns, accumulation is a hypernym of book; that is, accumulation is a word with a broader meaning than book:

book: a collection of rules or prescribed standards on the basis of which decisions are made
accumulation: several things grouped together or considered as a whole

Other hypernyms of book include aggregation, assemblage, collection.

As nouns, accumulation is a hypernym of book; that is, accumulation is a word with a broader meaning than book:

Other hypernyms of book include aggregation, assemblage, collection.

book (noun)	accumulation (noun)
physical objects consisting of a number of pages bound together	the act of accumulating
a number of sheets (ticket or stamps etc.) bound together on one edge	several things grouped together or considered as a whole
a written work or composition that has been published (printed on pages bound together)	(finance) profits that are not paid out as dividends but are added to the capital base of the corporation
a written version of a play or other dramatic composition; used in preparing for a performance	an increase by natural growth or addition
a compilation of the known facts regarding something or someone
a major division of a long written composition
a collection of rules or prescribed standards on the basis of which decisions are made
a collection of playing cards satisfying the rules of a card game
a record in which commercial accounts are recorded

book (verb)	accumulation (verb)
engage for a performance
record a charge in a police register
arrange for and reserve (something for someone else) in advance
register in a hotel booker