Why do we say “uncle” when admitting defeat? The only facts we know for sure are that it’s strictly a North American phrase, and that it first appeared in written English in 1918.
I am saying “uncle” with regard to “momentarily.”
When I first learned the word, its meaning was “for a moment,” as in
“He paused momentarily before entering the room.”
In North America, much to my chagrin, it has come to mean “in a moment” as well, leaving it up to the listener to determine its meaning from the context.
As many of you must know, it is common practice for flight attendants to announce that “the plane will be landing momentarily.” Clearly, they do not mean that the plane will be landing for a moment and will then become airborne again.
Why not save seven letters and four syllables and just say “soon”?