"She is a coward woman and is like a dog that chases speeding cars on roads, but steps back as and when the vehicle stops," he said while addressing a program in Mainpuri (UP).
Singh, whose abusive remarks against BSP chief Mayawati had recently caused an outcry, later retracted from his statement.
"I didn't compare her with a 'dog' instead I said that she and her ministers call us 'dogs'," Singh said.
The leader, who was arrested for allegedly making derogatory comments against the BSP chief in July, was last month released from Mau jail, after a local court granted him bail.
Singh had accused Mayawati of selling party tickets for the assembly elections next year to the highest bidder and then changing her mind when someone bid more.
Singh then used a derogatory term for Mayawati that had the entire opposition gunning for the BJP, and even senior BJP leaders distancing themselves from him.