Pronunciation: (hed'on', -ôn'),[key] —adj. 1. (of two objects) meeting with the fronts or heads foremost: a head-on collision. 2. facing the direction of forward motion or alignment; frontal.
3. characterized by direct opposition: a head-on confrontation.
—adv. with the front or head foremost, esp. in a collision: She stepped out of the front door and walked head-on into her husband.