Treat like dirt is an expression that means to treat someone or something with disrespect and contempt. The crossword solutions for this term are ABUSE, ABASE, and ILLUSE. ABUSE is to use something in a way that is not intended, such as using physical force against someone. ABASE is to lower someone's dignity or self-esteem. Illuse is to mistreat or misuse someone or something. All three words can be used to describe treating someone or something like dirt.