Definition of the word train on

The phrase "train on" originated in the military context, particularly during air defense training. It refers to the process of continuously tracking and monitoring incoming aircraft or missiles using radar or other detection systems, with the intent of intercepting and destroying the target. The term "train" in this context refers to the radar beam or searchlight used to detect the approaching enemy aircraft. The word "on" is used to indicate that the tracking process is ongoing and that the detection systems' focus remains on the target. The expression gained wider usage in recent decades due to its applicability in other fields such as data science, where it is used to describe the ongoing process of training machine learning algorithms on large datasets in order to improve their performance. Overall, the phrase "train on" reflects continued monitoring and adjustment of systems in order to achieve better performance and optimization in various applications.