Originally Posted by
choddo
In english, it’s become regarded as a nasty term in recent years, in any context, because it was used for a long time as an insult to disabled people and calling an object it was basically comparing that object to someone suffering from severe cognitive impairment.
of course, in French it’s a normal word.
When referring to ignition timing it's the right word, probably when talking about chemical reactions too, so I guess when used technically it's OK but when used generally it's definite poor form.