Whenever I encountered a new word on the internet I used to:

1. open a new tab
2. search the word definition
3. copy and paste it into a local file

These steps were inefficient and interrupted my reading. So I made a small browser extension using ajax:

function insertToDictionaryDB(term, url=document.URL) {
  var obj = {term: term, url: url}
  var response = $.ajax({
    type: 'POST',
    url: "http://localhost:3131",
    data: obj,
    dataType: 'text',
    success: function(d) { console.log("OK")},
    error: function() { console.log("Something went wrong") }
  });
}

document.addEventListener('keydown', function(e) {
  switch(true) {
    case e.ctrlKey && e.key === 'd': term = prompt('Term:'); url = prompt('URL:', document.URL); insertToDictionaryDB(term, url); break;
  }
}

This function (which is mapped to Ctrl+D) sends a json string with a term and url to a listening local server http://localhost:3131. The server searches the word definition, stores it in a database, and opens a dialog with the word definition. All triggered with a single keystroke, and without leaving the browser 👌.