I wonder if you should do something with HTTP codes here.  Use 404 if we didn't find it, and 200 if we did.  So something like:

```javascript
  res.send( !!word.length ? 200 : 404 );
```

After you switch to `findOne` it can just be:
```javascript
  res.send( !!word ? 200 : 404 );
```