[hed-on, -awn] 
| 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. |
| 4. | with the front or head foremost, esp. in a collision: She stepped out of the front door and walked head-on into her husband. |
head on
With the face or front first, as in The two bicycles collided head on. [Early 1800s]
In direct conflict, in open opposition, as in They decided to meet the opposition head on.