Scientifically means by the methods of careful testing and measurement. Scientifically proven, scientifically tested, scientifically speaking.
Scientifically proven is a phrase to distrust in advertising, since science supports claims rather than proving them outright. Used honestly it points at method: scientifically means somebody controlled for what else might explain it.
1adverbscientificallyBy the methods of careful testing and measurement.
“The claims made for the diet have never been scientifically tested.”
scientifically is a manner.
Medieval Latin
scientificus — pertaining to science
Middle French
scientifique
English
scientific
English, today
scientifically
From scientific + -ally. scientific Borrowed from Middle French scientifique, from Medieval Latin scientificus (“pertaining to science”).
Etymology from Wiktionary, CC BY-SA