"Smoke-free"

Walking through the campus, I often see posters or signs that says

“smoke-free”

I think many people get easily confused by its meaning.

Does that mean I can smoke here, or am not allowed? The phrase is tricky, indeed!

Being “free” sounds like “you can do anything as you wish.” 

You feel released from some ties and obligations, taking the word sounds highly positively.

Yet, you cannot take "smoke free" as such and smoke as you like. It means actually the opposite (as the sign clearly shows): "you are prohibited from smoking."

In this sense of "free," OED defines,

     3 (c). Clear of something which is regarded as objectionable or problematic. With of, from.

Fowler's Dictionary of Modern English Usage notes: 

"-free" is a suffix used in dozen's of common words such as acid-free (paper), alcohol-free, duty-free, fat-free, hands-free, interest-free, smoke-free, tax-free. A hyphen should separate it from the word it is joined to, i.e. alcohol-free not *alcohol free or *alcoholfree, hands-free rather than *handsfree or *hands free.  (327-28)

To be continued.

Works Cited:
Butterfield, Jeremy. ed. Fowler's Dictionary of Modern English Usage. 4th ed.Oxford Clarendon, 2015.