[X4U] Nixing an erroneous "to" name in Mail.app

[nk]

somehow, mail.app entered an incomplete spelling of a friend's name  
as an email entry; I was prbly too hasty, and tabbed to the subject  
line after typing a few letters of their name (perhaps not allowing  
Mail.app enuff time to link what I'd typed to an email addy, and I  
didn't correct what it did?)

Well, now, Mail.app thinks that that name fragment is an email  
recipient,  even though it has attached no email address to it,  
offers it up, and I have to scroll down to the legit ones to make  
sure the email actually gets sent out.

Tried searching for the fragment in address book, but it doesn't come  
up, only the correct one does.

Anyone know how I can track that rascal down and get rid of it?

thank you!

n