to make a serious mistake or spoil something
einen ernsthaften Fehler machen oder etwas verderben (einen ernsthaften Fehler machen oder etwas verderben)
"I really screwed up the presentation."
"Ich habe die Präsentation wirklich vermasselt." (Ich habe die Präsentation wirklich **vermasselt**)
to gradually weaken someone or something
a discovery that changes understanding in a field
an attempt to obtain sensitive information by deceit
to join someone to work or participate together
to tease or joke with someone in a playful way
to complete a task or promise as planned