اسم فلانی رو به زبون نیار چی میشه؟

Question

اسم سرهنگ رو به زبونت نیار.  اون آدم بود أدم! 

Answer 1

How about a quote from J.K. Rowling, from Harry Potter and the Order of the Phoenix? :-)

...You dare speak his name with your unworthy lips...

But seriously you can say 'speak ill of'

Don't speak ill of the colonel. He was a real man.

Don't talk about him like that. He was a good man.

http://www.urbandictionary.com/define.php?term=A%20real%20man

http://idioms.thefreedictionary.com/speak+ill+of

Note: Don't mention his name is also an option though it's often used when you want to say you don't want someone to speak of another because the latter did something unpleasant and you don't even want to hear their names maybe because it reminds you of what they did to you or when you want to tell someone not to make excuses by using someone else's reputation (in this case we say don't drag him into this)

Answer 2

Don't even mention the Colonel's name! He was not a man!