Yes, there is a way to import lyrics to iTunes. Practically, there are two ways: manually or automatic.
For the manual part, open iTunes then locate a track you already have the lyrics for. Use right click on the file or (Ctrl + Click for Mac) and choose Get Info. Once the windows opens, select the Lyrics tab. By default, the section is always empty. Paste the lyrics in the area and when you'll play the file, the lyrics will be available.
The automatic way involves in installing a plug-in called Get Lyrics. You can download it using the following URL. Install the application, then launch iTunes and play a file. Get Lyrics will automatically start providing you the lyrics for that file. From the options menu, click Tag Current to get the lyrics for the currently playing track.