Definition of ironclad. 1  1 : sheathed in iron armor âused especially of naval vessels. 2  2 : so firm or secure as to be unbreakable: such asa : binding an ironclad oathb : having no obvious weakness an ironclad case against the defendant.
Best Answer: CR means a credit. If this appears on the balance due line of your statement, it means that you owe nothing and that you are that much ahead of future charges and no payment or acknowledgment is needed.
A more specific definition in common use is an account with a balance that is the opposite of the normal balance (Dr/Cr) for that section of the general ledger. An example is an office coffee fund: Expense Coffee (Dr) may be immediately followed by Coffee-employee contributions (Cr).