[saalweachter]

That's easy; there are synonyms added for test but not for steve.

If you search for ["test" -test] you'll get no results; quoting "test" removes the synonyms.

It's probably not new behavior per se, but synonyms have gotten a lot broader over the years, so it was a lot easier to punch [term -term] ten years ago and hit a term which had no synonyms.

[IncRnd]

Correct, though it is new in the sense of this conversation, which compares to how a search used to be.

The point wasn't as to what the synonyms were for a specific search term but that they have been added as implicit terms, which makes google search no longer exact.

[fargle]

[test -test -tests -tested -testing] returns no results for me - teased out the synonyms!