I defiabuse as what went on in my yeshiva ketana. Rebbe’s would punch, slap and even kick us if they thought we weren’t paying attention. When the yeshiva would periodically fall months behind on salaries, the rebbe’s took their frustration out on us. This was in the late 1950’s. It did not engender a love of learning. There was also emotional abuse. Example:when I was nine , I went to my Rebbe after davening to say that I had concentrated real hard for half of the davening. His chizuk? He called me to the front of the class and ridiculed for davening hard for only half.
Somehow I did not go OTD, but I came close a few times until adulthood when other factors put yiddjzhkeit in a more favorable light. Many of my friends did go OTD. Contrary to some posters, sometimes it is the educators and parents ( who knew about the beatings but assumed them to be justified ) and not the kids unhappiness or emotional instability. My parents were not bad people, they just assumed this was how it was supposed to be in yeshiva
The yeshiva high school I went to didn’t use physicL abuse but ridiculed and shamed students if they didn’t like the questions that were asked