Come on Eileen
Swear [La La] means
[La La La] mean everything
Pretty white dress
[La La La La] ...ess
[La La La La]
Come on Elieen

Compare this to the real chorus:

Come on Eileen, well I swear (what he means)
At this moment, you mean everything
With you in that dress my thoughts I confess
Verge on dirty
Ah come on Eileen

The verses are also a little difficult to understand mainly due to the
backing vocals frequently singing over the top of the lead singers words.
Sometimes these backing vocals are repeating parts of the verse, at other
times they are adding in words. Furthermore, some words are barely audible
while others in the middle of the line tend to be stretched out - giving the
impression that it is either the last word in a line or the start of
another, when in fact it is in the middle.

This vocal structure gives the song is characteristic sound, and makes it a
lot of fun to sing along. You don't really need to know the lyrics, just
throw in the occasional 'Come On Eileen', 'Everything', 'Torra loora rye
aye' and '..ess'. If you want a crack at the lyrics, here they are:

Come on Eileen
Dexy's Midnight Runners (Dexys Midnight Runners)

Poor old Johnny Ray
Sounded sad upon the radio
He moved a million hearts in mono
Our mothers cried and sang along and who'd blame them
Now you're grown, so grown, now I must say more than ever
Go toora loora toora loo rye aye
And we can sing just like our fathers

Come on Eileen, well I swear (what he means)
At this moment, you mean everything
With you in that dress my thoughts I confess
Verge on dirty
Ah come on Eileen

These people round here wear beaten down eyes
Sunk in smoke dried faces
They're so resigned to what their fate is
But not us, no not us
We are far too young and clever
Eileen I'll sing this tune forever

Come on Eileen well I swear (what he means)
Ah come on, let's take off everything
That pretty red dress Eileen (tell him yes)
Ah come on Eileen