1. having no tread or worn smooth (especially of tires)

Examples

• The treadless tires were dangerous on wet roads.
• He needed to replace his treadless bicycle tires before the race.
• The mechanic warned that the treadless condition made braking difficult.
• Driving on treadless tires in winter is extremely hazardous.
• The old car had treadless tires that provided no grip on the pavement.