The noun lecturing refers to giving an instructional talk on some subject — usually in front of a class or a group of people. Despite your lecturing, the safety rules have not sunk in for this driver's ed class. Too many of the students still think it's okay to roll through a stop sign.
Lecturing has lecture as its base word. It's from the Latin word lectura, meaning a reading or lecture. Lecturing can mean an instructional talk or it can take the form of a stern, one-sided talk. Your kids may be used to the lecturing you do at home, but that doesn't mean they like it. If you notice they roll their eyes every time you start a sentence, you may want to consider dialing back a little on the lectures.