ac·count –noun
1. an oral or written description of particular events or situations; narrative: an account of the meetings; an account of the trip.
2. an explanatory statement of conduct, as to a superior.
3. a statement of reasons, causes, etc., explaining some event.
4. reason; basis: On this account I'm refusing your offer.
5. importance; worth; value; consequence: things of no account.
6. estimation; judgment: In his account it was an excellent piece of work.
7. an amount of money deposited with a bank, as in a checking or savings account: My account is now with Third National.
8. Also called charge account. an accommodation or service extended by a business to a customer or client permitting the charging of goods or services, the returning for credit of unsatisfactory merchandise, etc.: Do you have an account at this store? My account with the restaurant is past due.
9. a statement of financial transactions.
10. Bookkeeping. a. a formal record of the debits and credits relating to the person, business, etc., named at the head of the ledger account.
b. a balance of a specified period's receipts and expenditures.

11. Commerce. a. a business relation in which credit is used.
b. any customer or client, esp. one carried on a regular credit basis.
c. Also called advertising account. the business assigned to an advertising agency by a client: The toothpaste account was awarded to a new agency last year.

–verb (used without object) 12. to give an explanation (usually fol. by for): to account for the accident.
13. to answer concerning one's conduct, duties, etc. (usually fol. by for): to account for the missing typewriters.
14. to provide a report on money received, kept, and spent.
15. to cause (usually fol. by for): The humidity accounts for our discomfort. His reckless driving accounted for the accident.
–verb (used with object) 16. to regard; consider as: I account myself well paid.
17. to assign or impute (usually fol. by to): the many virtues accounted to him.
—Idioms18. call to account, a. to hold accountable; blame; reprimand: Call them to account for having endangered their lives.
b. ask for an explanation of.

19. give a good (bad, etc.) account of, to do something or conduct oneself in a good (bad, etc.) manner: She gave a good account of herself in the tennis tournament.
20. hold to account, to hold responsible; hold accountable or culpable: If any of the silver is missing, I'm going to hold you to account.
21. on account, as an installment or a partial payment: I can't pay the balance, but here's $10 on account.
22. on account of, a. by reason of; because of.
b. for the sake of: She saw it through on account of me.

23. on all accounts, in any case; under any circumstances. Also, at all accounts.
24. on no account, under no circumstances; absolutely not: On no account should you buy that painting without having it appraised.
25. take account of, a. to make allowance for; consider: One must take account of the difficult circumstances. Taking account of the high overhead, the price is not excessive.
b. to notice or observe.
Also, take into account.
26. turn to account, to derive profit or use from; turn to advantage: She has turned her misfortunes to account.

From: http://dictionary.reference.com/browse/account

a descriptive term for a measurement of quantity of beans, dollars, points, facts, etc. or a membership.

It's were you keep your money if you'd rather give all of your money to suit-wearing BMW-driving SOBS than keep it all hidden underneath your bed for your mum to find.