לְהַתְחִיל עִםlehatkhil im meaning in Hebrew
to hit on (someone) · verb + preposition (fixed expression)
Also spelled in English: lehatchil im

It's the verb you learned in your first month, but put a person after it and the whole bar knows what's going on. Say it in a sharper voice and אל תתחיל איתי means back off.
הבחור בבר התחיל איתי כל הערב, ובסוף התברר שיש לו חברה.
“The guy at the bar was hitting on me all evening, and then it turned out he has a girlfriend.”
Think of the last time someone made an obvious move on you or a friend—how would you describe it using התחיל איתי?