New use of "unless"?

[Laurence Horn]

At 11:47 AM -0500 1/23/01, Gregory {Greg} Downing wrote:
>At 11:27 AM 1/23/2001 +0800, you wrote:
>>This would be one of many cases where the OED's "obs." should really
>>be "obs. and dial."  I don't think "lest" necessarily figures in
>>"unlest".
>>
>>larry [horn]
>>
>
>The English Dialect Dictionary might help with the possible history of
>nonstandard "unle(a)st" between 1600 and 1900, but I don't have a copy here
>with me.

No listings; the only variants are "onless" and "unlessen".  No
"unlest" or "unleast" at all in Wright.

>It's hard to be sure where the "t" comes in. It could be liaison, as
>suggested earlier, and/or a natural enough (con)fusion of two conjunctions
>having similar sounds and not unrelated meanings, due (after all) to a
>geunine genetic link.
>
Again, I have to dissent.  I think it's more likely that, as Beverly
suggested, "unlest" is related (phonologically) to "acrosst" and
"oncet".  There's no sign that "lest" ('so that not', 'for fear
that') and "unless"--whether cousins or siblings--were ever usable
interchangeably; I've mostly used the former when I was translating
Lat. "ne" + subjunctive in high school but even those who do use it
seem to use it in a register-restricted way.

larry