[CQ-Contest] CW QUESTION - NOT SKIMMER RELATED

[Barry Merrill]

On a completely different CW topic, having heard
a snippet on a local non-profit FM radio station
claiming the source of "umpteen" was around 1905
from military morse code because "ump" was a dash, 
I can find that Wikipedia and many other sources
make the same claim:

"The word is apparently derived from the slang ump(ty),
a dash in Morse code (of imitative origin), plus -teen."

I've searched all of my resources for both American
and Internal Morse characters and can find nothing
for dash other than the old '-....-' punctuation,
which has none of the characteristics of U M or P.

Can anyone explain this claim?

73

Barry, W5GN