router.put('/update/:word', (req, res, next) => {
  // const word = new Word ({
  //   word: req.body.word,
  //   annotation: req.body.annotation,
  // });
  const {
    word,
    annotation,
  } = req.body;

  Word.updateOne({
      word: req.params.word,
      // annotation: req.params.annotation
    }).then(result => {
      if (result.nModified > 0) {
        res.status(200).json({
          message: "Update successful!"
        });
      } else {
        res.status(401).json({
          message: "Not authorised!"
        });
      }
    })
    .catch(error => {
      console.log(error);
      res.status(500).json({
        message: "Could not update word!"
      });
    })
});