From en.wiktionary.org:
** English
*** Alternative forms
- [en]
- [en] [minced oath]
*** Etymology
Merriam-Webster finds _tinker's damn_ in print since 1839 and suggests that it
derives from tinkers' reputation for swearing.[1] The spelling _tinker's dam_
is attested since 1858,[2] and phrases.org.uk notes the disagreement over
whether the term originated from tinkers' swearing or instead from their use
of small, single-use dams to hold solder.[3] The latter explanation has been
offered since 1877;<ref name="PhraseFinder"/>[4] on the other hand, the phrase
_tinker's curse_ is attested since 1824 and the phrase _worth a tinker's cuss_
is attested since 1854, for which reason Etymonline considers the "dam"
derivation an "ingeniously elaborate but baseless" invention of later
writers.<ref name="Etymonline"/>
*** Noun
[en]
1. An insignificant or worthless amount or thing .
2. * 1 MAY 1823 , _Mrs Chatterly_ , Anon in Ramblers Magazine, Vol 2 No 5, p. 216:
3. *: [...] is not worth (to use expression excited by honest indignation) a TINKER'S DAMN : and if Mrs. Chatterly has no other salvo for her precious reputation. [...]
4. * [en]
5. * {{ quote-text | en | year=2012 | title=w:Django Unchained
|passage=[...] and I wouldn't sell you a TINKER'S DAMN.}}
**** Synonyms
- [en] [chiefly British]
- [en]
**** Derived terms
- [en]
*** References
- The Maven's Word of the Day (see http://www.randomhouse.com/wotd/index.pperl?date=20000114)
- <!--another early attestation of the "tinker's dam" spelling--> 1868 March, _Mr. Thom. White's Little Sermon_ , in _Putnam's Magazine_ , page 555: "No, Peter; women, now, are not worth a tinker's mill-dam—that's what I think." [ ... ] Just what a "tinker's dam" is, I have no means of knowing; but I believe it to be something very worthless indeed.
References:
[1]. [url=https://www.merriam-webster.com/dictionary/tinker's%20damn]
[2]. 1858 December, January Searle, _Hyra, the gipsy Prophetess_ , chapter XXI, in _Frank Leslie's New Family Magazine_ , volume 3, number 6, page 546: " [ ... ] and I doesn't care a TINKER'S DAM about him."
[3]. [entry=A tinker's damn]
[4]. [entry=tinker]