This topic arose in connection with a mailing-list discussion about schaden- und klaglos halten, which is probably intended to be schad- und klaglos halten and is not necessarily an Austriacism.
The question arose (at least for me) whether you need a separate word for klaglos, or whether indemnify or hold harmless is sufficient alone. So it becomes a question of what the English terms mean – a question often asked by those translating into German when faced with pairs of terms in English.
I looked at Mellinkoff’s Dictionary of American Legal Usage, which is one of a number of books one can consult to see if doublets consist of words with different meanings, or if they could be rendered by one.
To summarize:
hold harmless: is understood to protect another against the risk of loss as well as actual loss. Whether or not it includes defense of lawsuits is sufficiently uncertain to warrant detailed provision.
indemnify: a) sometimes a synonym of hold harmless. The identity is made clearer in the expression indemnify against liability.
b) when distinguished from hold harmless, indemnify: to reimburse for any damage. This sense is spelled out as indemnify against loss
indemnify and hold harmless: a lawyer’s hedge against the imprecision of both expressions, by including assumption of loss and liability. Defense of lawsuits still best spelled out.
On the Web I found indemnify and keep indemnified (but I would think indemnify includes that), and also defend, indemnify and hold harmless. The best mailing-list suggestion was indemnify against loss and lawsuits. The indemnify against seemed wrong to me, but that was because I was thinking indemnify = for past loss and hold harmless = for future liability. The very preposition against seems to me to have a future sense in this context.
I don’t know if indemnify and keep indemnified is necessary. If you promise in a contract to indemnify someone, there’s no reference to ‘once only’.
This is all without asking the necessary question as to the meaning of schad- und klaglos halten.