> Tax avoidance is the avoidance of the required tax (an alternative name is tax evasion), tax minimisation is paying one's required tax and no more

It still isn't. Some sources:

Wikipedia - https://en.wikipedia.org/wiki/Tax_avoidance

> Tax avoidance is the legal usage of the tax regime in a single territory to one's own advantage to reduce the amount of tax that is payable by means that are within the law.

Investopedia - https://www.investopedia.com/terms/t/tax_avoidance.asp

> Tax avoidance is the use of legal methods to modify an individual's financial situation to lower the amount of income tax owed. This is generally accomplished by claiming the permissible deductions and credits. This practice differs from tax evasion, which uses illegal methods, such as underreporting income to avoid paying taxes.

Dictionary.com - http://www.dictionary.com/browse/tax-avoidance

> reduction or minimization of tax liability by lawful methods

Collins Dictionary - https://www.collinsdictionary.com/dictionary/english/tax-avo...

> Tax avoidance is the use of legal methods to pay the smallest possible amount of tax.

Freedic Legal Dictionary - https://legal-dictionary.thefreedictionary.com/tax+avoidance

> The process whereby an individual plans his or her finances so as to apply all exemptions and deductions provided by tax laws to reduce taxable income.

> Through tax avoidance, an individual takes advantage of all legal opportunities to minimize his or her state or federal Income Tax, gift tax, or estate tax. An individual may, for example, avoid federal income tax by investing a large sum of money in municipal bonds, since the interest on such bonds is not considered taxable income on which federal tax is due. Interest on the same amount of money placed in a savings account must be included as taxable income.

> From the perspective of tax collectors, avoidance is evasion and not minimisation.

This is misleading. Either may trigger an audit if the internally expected discrepancy is greater than the actual discrepancy, but an audit isn't criminal, and it takes an assertion of fraud (a violation of the law, which does not fall within legal avoidance strategies) to go from audit to criminality.

> Politicians also use the term "tax avoidance" as a synonym for "tax evasion" when it is useful to them.

Possibly. Politicians do all sorts of stupid shit. That has zero bearing on the definition of words.

> The problem that people face is that legal definitions quite often do not match the general populous understanding of the words used.

Right, which is why tax agencies interpret the law into tax code that is distributed to the populace* as clear and transparent. In the event that there's a failure at reconciliation between legislative intent on a tax policy and the interpreted code, that can be changed legislatively, clarified during reconciliation, or fixed through a variety of other means. The IRS is not authorized to re-interpret tax law to mean things it doesn't say, and while there's a certain amount of interpretive leeway, as a citizen, you can sue where you disagree.

> We can always argue over whether or not "tax avoidance" is the same as "tax evasion" or "tax minimisation".

We can, but since there are clear lexical, legal and tax definitions for each, it seems a stupid hill to die on. If people insist on using the wrong words, that can't be helped, but that doesn't mean that the right words don't exist.

> I am using the definitions of those terms as shared to me by my friends in taxation.

Not that it should be considered canon, but I have friends that work at the IRS, the SEC, and at FINCEN. I reached out to them, and they all think that your friends are wrong. /shrug.

It's probably worth clarifying that when I refer to agencies here, I'm referring specifically to American agencies. I don't have any clue on how other countries internally represent their laws, and I make no assertions as to how they operate. I have no idea.

> Lastly, if in America, the IRS is bound by those same laws as the citizenry, why are the so many documented cases of the IRS "draining" the bank accounts of so many little people when nothing illegal has been done? The IRS has interpreted the law by their own internal definitions.

Well, they can't drain your account, but they can freeze your funds. As to the 'why', it's because there are laws that expressly authorize them to do so. The IRS has express legal authority to issue a bank levy to freeze accounts in the event of certain activities or suspicion of certain activities. Note that 'having legal authority' to do something does not connote to 'having extralegal authority' to do something. They are bound by the same laws that you and I are, and those laws authorize them to do something. While speaking practically, they might be able to freeze accounts for no reason at all, but they are breaking the law in doing so because they do not have legal authority to freeze accounts for funsies.