Does the word “umpty” have two different meanings?

Question

I happened to learn the word “umpty” in association with “umpteen” appearing in the following sentence in the article titled “Obama’s Gitmo Problem” in May 24 New York Times:

Late Wednesday afternoon, President Obama made his big national security speech — in which he said, for the umpteenth time, that the prison in Guantánamo Bay, Cuba, should be closed.

Both Merriam-Webster online dictionary and Readers English Japanese Dictionary at hand define ‘umpty’ as ‘such and such,’ in the same wording with an example, ‘umpty percent of all new houses’ in Merriam Webster. It sounds like simply saying ‘a certain’ or 'X' against an unidentifiable number or thing.

While both ‘Free dictionary’ and ‘Dictionary com’ define it as ‘an indefinite, fairly large number’ in the same wording.

Though implications of ‘such and such’ looks different from ‘an indefinite, large number’ to me, are all saying the same thing, or there are two different meanings in this word?

Neither Cambridge nor Oxford Dictionary carries this word. Is ‘umpty’ popular English word?

Can you give me a couple of examples of the use of “umpty” other than ‘umpty percent of something’’?

Answer 1

Umpty is a rare word and does not have a well-established meaning. The vast majority of uses in the Google corpus are as a nonsense word or placeholder (e.g., “Mr. Umpty Ump.”). The Online Etymology Dictionary notes the placeholder sense “of an indefinite number” (1905) and how it relates to umpteen (1917, WWI army slang). This latter word did catch on, with the related meaning “relatively large but unspecified in number.”

In summary:

• Umpty means “placeholder” or “unspecified number.” It is not a common word.
• Umpteen means “unspecified (large) number.” It is a relatively common word.

Answer 2

I only hear umpty in the phrase umpty diddly which means "a lot". (Examples from a web search - you won't need to click any links, just look at the previews of the results, where you'll see "don't wear them out with umpty-diddly phone calls about silly things", "If you are going to sue somebody for umpty-diddly dollars", "the hard-copy books I've accumulated over umpty diddly years" and so on.) That's a British usage - Americans use diddly to mean none at all, especially in diddly squat. In general ump is a placeholder syllable so umpteen means "ten plus something" and umpty means "ten times something" and umpety ump means "mumble mumble something something". Placeholders.

I don't see a distinction between ‘such and such’ and ‘an indefinite, large number’ in this context. They both mean "a number I am making up." If you were sure that less than 1% of all new houses met some criteria, and someone said that umpty percent did, you might argue with them and say something like "no way! I think it's hardly any, less than one percent even!". This is because umpty, like twenty, thirty, forty, etc suggests a multiple of ten. A largish number for percentages.