That means protest. In this particular case it means hissing, however.
But as far as I can tell, this has something to do with moving forward the cause for women or womanhood or femaleness or whatever. So it’s necessary or something.
Ivanka Trump defended her father at a women’s panel in Berlin Tuesday after attendees hissed and booed when she attempted to champion her father’s commitment to women’s issues.
„Einige Sichtweisen ihres Vaters über Frauen in der Vergangenheit lassen es fraglich erscheinen, wie er Frauen wirklich stärken will.”

You have to admit: Ivanka is hotter than most of your Beautiful Germans of the week. Stack one up for the USA!