Use badly

• Ride roughshod over
• "This one's on me"
• Morph is going to deal with abuse
• Act cruelly toward
• One will cut down oak, say, upset thanks to abuse
• Handle meanly
• Do wrong by

Wiktionary Word definitions in Wiktionary
vb. (alternative form of ill-treat English)

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Illtreat \Ill`treat"\, v. t. To treat cruelly or improperly; to ill use; to maltreat. Syn: mistreat, maltreat, abuse, ill-use.