Hi Lulu, "Du wirst dich noch umgucken" bedeutet: - Du wirst dich noch wundern. - Das wirst du noch bereuen. Am häufigsten wird "Du wirst dich noch wundern." benutzt.

Another version is: "Du wirst doch noch wundern!" It's simple said a kind of threat or a (almost always negative) preannouncement or even a warning. For example, a kid refuses to do his homework because he thinks he won't need that stuff in life anyway. Then the mother comes and says something like "If you don't learn this, >dann wirst du dich bei der Arbeit noch umgucken<" Meaning, "If you don't learn this, you'll be screwed when the exam comes around" :D