Not easy. A three word title song from the DT that fits is The swinish multitude.

For five words: Some versions of 'Off to sea no more' have these words only in the last verse.

For two words: Johnny McEvoy sings 'Croppy boy' with these two words only once, namely as the last two.

If you think this is solved or have given up on it and look for a new quest:

A traditional song in the DT with a single word title and this word doesn't appear in the song at all in its many many verses (after the title, of course).

Wolfgang