>Nice try. Not really the same thing. Nobody I know commonly says 'Internal combustion engines' when they mean 'motors' or 'engines'. Equestrian Events is a bit closer but not quite there yet because 'show jumping' is just a type of equestrian event. "minus two" is not a type of negative number, it is a negative number. A closer example would be commonly referring to a semi as a 'vehicle' while calling a group of semis, 'trucks'.

A semi-what? The semi-, demi- and another one (hemi- probably) all mean half-.