Is it any worse or more ambigious than "high pressure" or "low temperature"?
I think so. At least high or low has a useful relative meaning. For one thing I'd argue an "absolute" vacuum is physically impossible, so all "vacuums" are "partial". On a more philosophical side, a vacuum is a state of being, and how can you have a partial state of being? To me it sounds a bit like describing someone as "partially alive". You're either alive or your dead. You either have vacuum or you don't. What a person really means is that the pressure in the pipette is lower than some external reference point.
I know, it's a point of semantics because we all understand what is meant. But still... I find the phrase inexplicably annoying.
Sorry, didn't mean to derail the thread.