JSFiddle - React, Tailwind, and code Playground

HTML

<div class="item">
<div>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin nisi ligula, dapibus a volutpat sit amet, mattis et dui. Nunc porttitor accumsan orci id luctus. Phasellus ipsum metus, tincidunt non rhoncus id, dictum a lectus. Nam sed ipsum a lacus sodales eleifend. Vestibulum lorem felis, rhoncus elementum vestibulum eget, dictum ut velit. Nullam venenatis, elit in suscipit imperdiet, orci purus posuere mauris, quis adipiscing ipsum urna ac quam.</div>  
</div>

CSS

.item { 
    width: 300px; height: 120px; overflow: hidden; background-color: red;
}

.item div { padding: 10px; margin: 0;}

JavaScript

var item=Ext.select('.item div').first();
var divh=Ext.select('.item').first().getHeight();

while (item.getComputedHeight()>divh) {
    item.dom.innerText = item.dom.innerText.replace(/\W*\s(\S)*$/, '...');
}