JSFiddle - React, Tailwind, and code Playground

HTML

<div id="sections-usml-img-square">
anglais<br/>
boxe<br/>
cycliste
</div>

JavaScript

var gettxtsections = document.getElementById("sections-usml-img-square").innerHTML;
var sectionssearch = {
          "anglais":"cours d\'anglais",
          "boxe":"Boxe Thaï - Kick Boxing - K1",
          "cycliste":"Cyclisme",
          "moderne":"Danse Classique - Modern Jazz - GRS"
};
 
var newtxt = gettxtsections.replace(/anglais|boxe|cycliste|moderne/g, function(matched){
  	return sectionssearch[matched];
});
document.getElementById("sections-usml-img-square").innerHTML = newtxt;