Speak/think ill of somebody

Pro Tip 1/3

The phrase often implies malice or intent to harm someone's reputation.

After the argument, she began to speak ill of her friend to others.

Pro Tip 2/3

It's commonly used in private conversations, not in the person's presence.

Be wary, as some might speak ill of you once you're not there to defend yourself.

Pro Tip 3/3

The phrase is casual and might be considered rude in formal situations.

In the meeting, he spoke ill of our boss and shocked everyone.