To state a fact in a way that allows no doubt. To have no objection to.

This is another of those ancient phrases that we accept with our mother's milk as an idiom but which seem quite strange when we later give it some thought. When we are trying to convey that we acknowledge or have no objection to something, why bring bones into it?

It has been suggested that the bones are dice, which were previously made from bone and are still called bones in gambling circles. That explanation doesn't stand up to scrutiny - 'to make no dice about it' makes little sense. Also, in a 1542 translation of Erasmus's Paraphrase of Luke he discussed the command given to Abraham to sacrifice Isaac and wrote that 'he made no bones about it but went to offer up his son.' Erasmus wasn't noted for his visits to the gaming tables and would hardly have used gambling terminology to discuss a biblical text.

The source is likely to be more prosaic. There is an earlier phrase, 'to find bones in', meaning to have an objection to. This refers to the unwelcome discovery of bones in soup. So, bones = bad, no bones = good.

The earliest citation comes from the Paston Letters, which are a collection of texts from 1459 which refer to a dispute with Sir John Fastolf. In that Paston includes the line:

"And fond that tyme no bonys in the matere. (and found that time no bones in the matter)."

The context of the quotation is one where the litigants are accepting a verdict with no objection.