Post History
[Etymonline:] mid-15c., earlier onlesse, from on lesse (than) "on a less condition (than); see less. The first syllable originally on, but the negative connotation and the lack of stress changed ...
Question
etymology
#1: Initial revision
by
PSTH
·
2021-11-08T12:00:50Z (about 3 years ago)
How did 'unless' evolve to mean 'if not'?
>[[Etymonline:]](http://www.etymonline.com/index.php?allowed_in_frame=0&search=unless&searchmode=none) mid-15c., earlier *onlesse*, from *on lesse* (than) "`on a less condition (than)`; see [less](http://www.etymonline.com/index.php?term=less&allowed_in_frame=0). The first syllable originally [on](http://www.etymonline.com/index.php?term=on&allowed_in_frame=0), but the ***negative*** connotation and the lack of stress changed it to *un-*. ... [*OED* (3rd edn, 2017)](http://www.oed.com/view/Entry/215075?redirectedFrom=unless#eid): >[[†](http://public.oed.com/how-to-use-the-oed/key-to-symbols-and-other-conventions)A.] 2. Forming a conjunctional phrase introducing a case in which an exception to a preceding (or following) statement will or may exist: except if, **if..not**. 1\. How did `on a less condition (than)` shift to mean **if not**? 2\. What and where is the '***negative*** connotation'?