Hi Liz (ae in de),
I'm not asking that a dictionary should
always list the things a word doesn't mean, but in the case of inflammable, every dictionary I know, my Webster's Collegiate at home, my Webster's New College (actually a Houghton Mifflin production) here at work, and Wikipedia all have notes about it. Here's what Wikipedia says:
The word “inflammable” came from Latin “'inflammāre” = “to set fire to,” where the prefix “'in-”' means “in” as in “inside”, rather than “not” as in “invisible” and “ineligible”. Nonetheless, “inflammable” is often erroneously thought to mean “non-flammable”. To avoid this safety hazard, “flammable”, despite not being the proper Latin-derived term, is now commonly used on warning labels when referring to physical combustibility.http://en.wikipedia.org/wiki/InflammableMy office dictionary also notes that "flammable" had a brief life in the early 19th century and was deliberately resurrected by safety officials in the 20th century "in order to eliminate possibly dangerous confusion about the combustibility of various materials.
I have heard people, particularly politicians, use "arguably" to mean "unarguably" or "inarguably." I think that is the original question in the OP. And if one is translating from English to German, one should know about the possibility of that duality of meaning, or you run the risk of mistranslation, an error of omission. The only way to be sure is overall context, and if there is no context, then just go with what is dictionary-right.
If you attend a baby shower and all you hear is "Our baby's PJs are inflammable," then be shocked and horrified and proceed to correct them. If instead you hear in context "We're so relieved! Our baby's PJs are inflammable," then smile and congratulate them for being so concerned about safety and get another piece of cake. :-)
Also, focus should be on the thread, not on the contributors to the thread.